How long does it take for a blood test to come back?

Whenever we get a blood test performed we may say, “Why does it take so long?” If we suspect we have an illness or we are just not feeling well, then we are doubly anxious to get our test results. So, how long does it really take to get back medical lab test results. Depending on the test performed, most tests are completed and reported to your ordering healthcare provider within about 24 hours of receiving the sample for testing. One example of this, would be a cholesterol test or glucose test. Every test has what laboratories call a “turnaround time”. Remember that phrase! The “turnaround time” is how long it takes a laboratory to get a result for a particular test. So, a cholesterol and glucose test has a turnaround time of 1 day. A urine culture test has a turnaround time of 2-3 days. Keep in mind that certain tests take several days or several weeks. So, the next time you go to get your blood drawn, sound intelligent and ask the phlebotomist (the person doing the blood draw) or your doctor this question: What is the turnaround time(s) for my test(s)?
You can also simply ask your healthcare provider to contact you when your test results have been received. Before even leaving the doctor’s office ask your physician how soon he or she expects your test results to be available and how long you should wait before contacting the office if you have not received any news about your test results. Remember that no news is not always good news! Believe it or not sometimes the doctor’s office forgets to call you, claims to have never received your results or may file your lab tests away without informing you first.
Using myself as an example, I was feeling unusually sluggish and went in for a checkup. I didn’t hear from the doctor after several days so I called the office. I knew my blood tests must have been received already. They put me on hold (I did enjoy the elevator music) …it turns out that I was anemic. Oh, I’m feeling much better now in case you were worried (you can still send me a get well card). But I had to call the office. I had to take initiative. You, as the patient, must take control of your own medical laboratory tests. Remember about 70% of medical practitioners use medical lab test results to make their decisions. Be proactive and alert! Don’t leave it to doctor’s offices to call you if you think something is wrong. I can tell you, having worked for a major medical laboratory and dealing first hand with various doctor’s office across various fields, many doctor’s offices are just not that organized!
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Blood Test: Lead

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What Is a Blood Test?

A blood test is when a sample of blood is taken from the body to be tested in a lab. Doctors order blood tests to check things such as the levels of glucose, hemoglobin, or white blood cells. This can help them detect problems like a disease or medical condition. Sometimes, blood tests can help them see how well an organ (such as the liver or kidneys) is working.

What Is a Lead Test?

A lead test measures how much lead is in the blood. Lead is a metal that is found in the environment and in many consumer products. Most people have a small amount of lead in their blood from these exposures.

But higher levels of lead can lead to problems in children, such as learning disabilities, behavior problems, and anemia. Very high levels can cause serious problems, such as seizures or a coma.

Why Are Lead Tests Done?

A lead test may be done if a child is at risk for a high lead level. For example, kids who live in older homes or in communities with many older homes are at risk for high lead levels.

How Should We Prepare for a Lead Test?

Your child should be able to eat and drink normally unless also getting other tests that require fasting beforehand. Tell your doctor about any medicines your child takes because some drugs might affect the test results.

Wearing a T-shirt or short-sleeved shirt for the test can make things easier for your child, and you also can bring along a toy or book as a distraction.

How Is a Lead Test Done?

Most blood tests take a small amount of blood from a vein. To do that, a health professional will:

  • clean the skin
  • put an elastic band (tourniquet) above the area to get the veins to swell with blood
  • insert a needle into a vein (usually in the arm inside of the elbow or on the back of the hand)
  • pull the blood sample into a vial or syringe
  • take off the elastic band and remove the needle from the vein

Lead is sometimes tested with a “fingerstick” test. The health professional will clean your child’s finger, then prick the tip of it with a tiny needle (or lancet) to collect the blood.

In babies, blood draws are sometimes done as a “heel stick collection.” After cleaning the area, the health professional will prick your baby’s heel with a tiny needle (or lancet) to collect a small sample of blood.

Collecting a sample of blood is only temporarily uncomfortable and can feel like a quick pinprick.

Can I Stay With My Child During a Lead Test?

Parents usually can stay with their child during a blood test. Encourage your child to relax and stay still because tensing muscles can make it harder to draw blood. Your child might want to look away when the needle is inserted and the blood is collected. Help your child to relax by taking slow deep breaths or singing a favorite song.

How Long Does a Lead Test Take?

Most blood tests take just a few minutes. Occasionally, it can be hard to find a vein, so the health professional may need to try more than once.

What Happens After a Lead Test?

The health professional will remove the elastic band and the needle and cover the area with cotton or a bandage to stop the bleeding. Afterward, there may be some mild bruising, which should go away in a few days.

When Are Lead Test Results Ready?

Blood samples are processed by a machine, and it may take a few hours to a day for the results to be available. If the test results show signs of a problem, the doctor might order other tests to figure out what the problem is and how to treat it.

Are There Any Risks From Lead Tests?

A lead test is a safe procedure with minimal risks. Some kids might feel faint or lightheaded from the test. A few kids and teens have a strong fear of needles. If your child is anxious, talk with the doctor before the test about ways to make the procedure easier.

A small bruise or mild soreness around the blood test site is common and can last for a few days. Get medical care for your child if the discomfort gets worse or lasts longer.

If you have questions about the lead test, speak with your doctor or the health professional doing the blood draw.

Blood Tests

Some of the most common blood tests are:

  • A complete blood count (CBC)
  • Blood chemistry tests
  • Blood enzyme tests
  • Blood tests to assess heart disease risk

Complete Blood Count

The CBC is one of the most common blood tests. It’s often done as part of a routine checkup.

The CBC can help detect blood diseases and disorders, such as anemia, infections, clotting problems, blood cancers, and immune system disorders. This test measures many different parts of your blood, as discussed in the following paragraphs.

Red Blood Cells

Red blood cells carry oxygen from your lungs to the rest of your body. Abnormal red blood cell levels may be a sign of anemia, dehydration (too little fluid in the body), bleeding, or another disorder.

White Blood Cells

White blood cells are part of your immune system, which fights infections and diseases. Abnormal white blood cell levels may be a sign of infection, blood cancer, or an immune system disorder.

A CBC measures the overall number of white blood cells in your blood. A CBC with differential looks at the amounts of different types of white blood cells in your blood.


Platelets (PLATE-lets) are blood cell fragments that help your blood clot. They stick together to seal cuts or breaks on blood vessel walls and stop bleeding.

Abnormal platelet levels may be a sign of a bleeding disorder (not enough clotting) or a thrombotic disorder (too much clotting).


Hemoglobin (HEE-muh-glow-bin) is an iron-rich protein in red blood cells that carries oxygen. Abnormal hemoglobin levels may be a sign of anemia, sickle cell anemia, thalassemia (thal-a-SE-me-ah), or other blood disorders.

If you have diabetes, excess glucose in your blood can attach to hemoglobin and raise the level of hemoglobin A1c.


Hematocrit (hee-MAT-oh-crit) is a measure of how much space red blood cells take up in your blood. A high hematocrit level might mean you’re dehydrated. A low hematocrit level might mean you have anemia. Abnormal hematocrit levels also may be a sign of a blood or bone marrow disorder.

Mean Corpuscular Volume

Mean corpuscular (kor-PUS-kyu-lar) volume (MCV) is a measure of the average size of your red blood cells. Abnormal MCV levels may be a sign of anemia or thalassemia.

Blood Chemistry Tests/Basic Metabolic Panel

The basic metabolic panel (BMP) is a group of tests that measures different chemicals in the blood. These tests usually are done on the fluid (plasma) part of blood. The tests can give doctors information about your muscles (including the heart), bones, and organs, such as the kidneys and liver.

The BMP includes blood glucose, calcium, and electrolyte tests, as well as blood tests that measure kidney function. Some of these tests require you to fast (not eat any food) before the test, and others don’t. Your doctor will tell you how to prepare for the test(s) you’re having.

Blood Glucose

Glucose is a type of sugar that the body uses for energy. Abnormal glucose levels in your blood may be a sign of diabetes.

For some blood glucose tests, you have to fast before your blood is drawn. Other blood glucose tests are done after a meal or at any time with no preparation.


Calcium is an important mineral in the body. Abnormal calcium levels in the blood may be a sign of kidney problems, bone disease, thyroid disease, cancer, malnutrition, or another disorder.


Electrolytes are minerals that help maintain fluid levels and acid-base balance in the body. They include sodium, potassium, bicarbonate, and chloride.

Abnormal electrolyte levels may be a sign of dehydration, kidney disease, liver disease, heart failure, high blood pressure, or other disorders.


Blood tests for kidney function measure levels of blood urea nitrogen (BUN) and creatinine (kre-AT-ih-neen). Both of these are waste products that the kidneys filter out of the body. Abnormal BUN and creatinine levels may be signs of a kidney disease or disorder.

Blood Enzyme Tests

Enzymes are chemicals that help control chemical reactions in your body. There are many blood enzyme tests. This section focuses on blood enzyme tests used to check for heart attack. These include troponin and creatine (KRE-ah-teen) kinase (CK) tests.


Troponin is a muscle protein that helps your muscles contract. When muscle or heart cells are injured, troponin leaks out, and its levels in your blood rise.

For example, blood levels of troponin rise when you have a heart attack. For this reason, doctors often order troponin tests when patients have chest pain or other heart attack signs and symptoms.

Creatine Kinase

A blood product called CK-MB is released when the heart muscle is damaged. High levels of CK-MB in the blood can mean that you’ve had a heart attack.

Blood Tests To Assess Heart Disease Risk

A lipoprotein panel is a blood test that can help show whether you’re at risk for coronary heart disease (CHD). This test looks at substances in your blood that carry cholesterol.

A lipoprotein panel gives information about your:

  • Total cholesterol.
  • LDL (“bad”) cholesterol. This is the main source of cholesterol buildup and blockages in the arteries. (For more information about blockages in the arteries, go to the Diseases and Conditions Index Atherosclerosis article.)
  • HDL (“good”) cholesterol. This type of cholesterol helps decrease blockages in the arteries.
  • Triglycerides. Triglycerides are a type of fat in your blood.

A lipoprotein panel measures the levels of LDL and HDL cholesterol and triglycerides in your blood. Abnormal cholesterol and triglyceride levels may be signs of increased risk for CHD.

Most people will need to fast for 9 to 12 hours before a lipoprotein panel.

Blood Clotting Tests

Blood clotting tests sometimes are called a coagulation (KO-ag-yu-LA-shun) panel. These tests check proteins in your blood that affect the blood clotting process. Abnormal test results might suggest that you’re at risk of bleeding or developing clots in your blood vessels.

Your doctor may recommend these tests if he or she thinks you have a disorder or disease related to blood clotting.

Blood clotting tests also are used to monitor people who are taking medicines to lower the risk of blood clots. Warfarin and heparin are two examples of such medicines.

How Often Should You Get Blood Work Done?

It’s not uncommon for your doctor to recommend blood tests from time to time. However, some people aren’t clear on what these tests actually entail.

The tests that your doctor orders will likely depend on several factors, including:

  1. Age
  2. Medical history
  3. Family history
  4. Lifestyle

If you have concerns about your health and would like to talk with a doctor about blood tests, CareNow® urgent care is a great choice.

Open seven days a week and available on a walk-in basis, CareNow offers over 50 different medical tests and exams for patients over 3 months old.

Some lab tests, such as a complete blood count, can be performed on-site for quick diagnosis and treatment.

Find a CareNow® Urgent Care near you

Web Check-In®

How Often Should You Have Blood Work Done?

Your doctor will recommend which blood tests you should have and how often.

Generally, if your cholesterol is normal, you can repeat this test every five years. However, you should be tested annually if you have unhealthy levels or if you have a family history of heart disease or high cholesterol.

During your 20s, you should get your blood sugar checked and be tested for HIV. Your doctor will recommend how often you should have these tests repeated.

What Is a Complete Blood Count?

If your doctor has ordered a complete blood count, he or she is requesting a test that measures the cells that make up your blood. This includes:

  1. Red blood cells, which carry oxygen
  2. White blood cells, which fight infection
  3. Hemoglobin, the oxygen-carrying protein in red blood cells
  4. Hematocrit, the ratio of red blood cells to the total volume of blood
  5. Platelets, which help with blood clotting

This test is used to check for anemia, to monitor an existing blood condition, to see how medications are working, to diagnose health issues or as part of a routine checkup.

What Does a Blood Test Show?

A routine blood test will show if your blood levels fall within a normal range. If your levels fall outside the normal range, it could be because of a disorder or disease.

Other factors that can affect blood levels include:

  1. Physical activity level
  2. Alcohol intake
  3. Medications

Getting routine blood work is essential for diagnosing a number of diseases and conditions, as well as checking blood glucose and cholesterol levels.

Although some diseases and medical problems can’t be diagnosed via blood work, knowing your numbers can help you and your doctor learn more about your health.

Normal Blood Count Levels

When you get your complete blood test done, your doctor will check to make sure your levels are within a healthy range.

These numbers vary for men and women. The following blood count levels are considered healthy:

White Blood Cell Count Range

While the number of white blood cells can vary, the normal range is typically between 4,000 and 11,000 per microliter (mcL) of blood.

If you are showing a total white blood count of less than 4,000 per mcL, it could be a sign that your body isn’t able to fight off infection the way it should. When someone has a low white blood cell count, it is called leukopenia.

Do You Have to Fast Before a Blood Test?

Determining whether you need to fast before a blood test depends on the type of blood test that you are having.

Tests for blood glucose, blood cholesterol, gamma-glutamyl transferase and iron all require you to fast beforehand.

There is a chance that you may also be asked to fast for a basic or comprehensive metabolic test, renal function panel and vitamin B12 test.

Blood Tests Every Woman Should Have

Healthcare providers recommend that women have specific blood tests to monitor their health. Here are some of these crucial tests:

  1. Cholesterol and triglyceride levels
  2. Thyroid check
  3. Screenings for sexually transmitted infections and diseases
  4. Blood sugar level
  5. Vitamin D level

Can A Blood Test Detect Cancer?

If your doctor suspects that you may have cancer, he or she will likely recommend certain blood tests or other lab work that can help provide a proper diagnosis.

While it is difficult for blood tests to completely determine whether cancer or another noncancerous condition is present (with the exception of blood cancers), these tests can offer some guidance.

Common blood tests used to diagnose cancer include complete blood count, blood protein testing, tumor marker tests and circulating tumor cell tests.

Can A Regular Blood Test Detect HIV?

A common misconception regarding routine blood work is that it automatically includes a test for HIV. This is not the case.

Medical professionals are encouraged to routinely offer HIV testing to patients who live in areas where the disease is a common medical problem and to those whose lifestyles put them at a heightened risk of HIV.

Recommended Annual Blood Tests

During an annual physical exam, your doctor may order a complete blood count test and

A complete blood count test can reveal early signs of many disorders such as anemia, which can cause you to feel tired and listless.

A basic metabolic profile tests a number of elements in your blood, including:

  1. Blood sugar (or glucose)
  2. Calcium
  3. Electrolytes
  4. Creatine
  5. Kidney function

A comprehensive metabolic profile (CMP) adds screenings for:

  1. Cholesterol levels
  2. Protein levels
  3. Liver function

How Long Does a Blood Test Take?

If your veins are easily visualized and accessed, the blood draw process is typically very quick— usually 5 to 10 minutes.

If your veins are harder to find, it may take a little more time.

How Long Does It Take for Blood Test Results?

How long it takes to receive the results from your blood tests depend on where the tests are analyzed and the types of tests that your doctor orders.

Many of the lab tests performed by CareNow® are available on-site for quick diagnosis and treatment. The most common include the rapid flu test and strep tests—both available within minutes.

Abnormal Blood Work

If you’ve ever been called back to your doctor’s office because of an abnormality in your blood work, you know how scary it can be. But keep in mind that even if you have an abnormal blood test, you don’t necessarily need to worry.

Instead of thinking of your blood work as a pass or fail test, consider it more like a reference range.

Abnormal results don’t mean you have an illness or that something is wrong. Your doctor will interpret the meaning of your lab tests and decide what, if anything, should be done to correct any irregularities.

Where To Get Blood Work Done

If you are in need of blood work, routine or otherwise, consider visiting your local CareNow®.

Additional blood tests offered by CareNow® include:

  1. Thyroid tests
  2. Hormone tests
  3. STD tests
  4. Cholesterol screening

Make sure to utilize Web Check-In® to wait from the comfort of your home before your visit!

Web Check-In®


1) Andrew Brookes / Getty Images


American Association for Clinical Chemistry: “Complete Blood Count.”

American Family Physician: “Problem Drinking and Alcoholism: Diagnosis and Treatment.”

BMJ Open: “Diagnostic Accuracy of Calculated Serum Osmolarity to Predict Dehydration in Older People: Adding Value to Pathology Laboratory Reports.” “Guide to Blood Testing.”

JAMA Neurology: “Time Course and Diagnostic Accuracy of Glial and Neuronal Blood Biomarkers GFAP and UCH-L1 in a Large Cohort of Trauma Patients With and Without Mild Traumatic Brain Injury.” “Basic Metabolic Panel.”

National Heart, Lung and Blood Institute: “Types of Blood Tests,” “What Do Blood Tests Show?”

NHS: “Should I have a PSA Test?”

Northwestern Medicine, Feinberg School of Medicine: “First Blood Test to Diagnose Depression in Adults.”

Science: “Comprehensive Serological Profiling of Human Populations Using a Synthetic Human Virome.”

Scientific Reports: “Protein Profiling Reveals Consequences of Lifestyle Choices on Predicted Biological Aging.”
The National Academies of Sciences, Engineering, Medicine: “Problems in Detecting Concussions.”
FDA: “Tests Used in Clinical Care.” “Knowing If You Are Pregnant.”


How long should I wait after a cold before getting my blood test?

5 September 2016. Related: All topics, CD4 and viral load, Other tests.

I have a cold/slight touch of the flu and I was due for my blood tests today, however I have reschedule them until next week. My question is: how long does it take for your CD4 to go back my normal range… How long should I wait after a cold before getting my blood test?


Answer: Muirgen Stack


Thanks for your question.

Your CD4 count and viral load can be affected by other viruses, such as the flu. It is possible therefore that your test results might be affected by your recent infection. Unfortunately as everyone has a unique immune system, the time it takes to recover from a cold or flu will vary and this may be reflected in your test results. It’s also worth noting that a cold will likely have less of an effect than definite flu (influenza).

As this may be hard to predict, you can ask the doctor to check CD4 percentage as well as your CD4 count. Follow this link for more information about CD4%.

It’s also possible that your viral load could blip above undetectable because of an infection. If your viral load has increased you should have another test to check the result. This means you may be better off going for your tests as planned and rescheduling them again if anything looks out of the ordinary. You can also give your clinic a call beforehand and ask if they have any recommendations for rescheduling.

Reason behind testing blood when someone is suffering from Common cold and fever?

There are differences between individual clinicians’ ways of approaching things, and regional ones as well, so I can’t speak for every clinician.

But respiratory infections are one of the most common reasons why someone comes into primary care or urgent care, and there are common approaches.

When someone comes in with cold symptoms, many factors that are taken into consideration. Based on those factors, clinician might order lab tests or might not.

The reason is that the differential diagnosis of respiratory infections is broad.

  • Many viruses like the cold and flu
  • Pneumonia (primary bacterial or superimposed after viral infection)
  • Bronchitis
  • Bacteria like strep throat or sinus infection
  • Allergies
  • Chemical irritation

Pneumonia and sinus infections (and very rarely blood infections or meningitis) are possible after a viral infection because the mucus from the cold sitting in the sinuses/lungs are a place bacteria like to grow in. Those are usually the only times antibiotics are worthwhile.

You mentioned symptoms “I have a cold.” Those aren’t symptoms. Symptoms are

  • cough (dry or productive of sputum)
  • runny nose
  • sore throat
  • hoarse voice
  • headache
  • body aches
  • fevers or chills
  • fatigue
  • bleeding
  • nasal congestion
  • weakness
  • lightheadedness
  • nausea/vomiting

The constellation of symptoms and timeline are the primary things that tell us WHAT the infection is. Adding vital signs (temp, blood pressure, pulse) and a physical exam, often we don’t even need labs/tests.

But when they do, labs/tests they might get are:

  • Nasopharyngeal swab if they suspect flu and want to be certain, or a viral panel for rhinovirus etc
  • Throat swab / culture for suspicion of strep throat
  • Chest XRay if there’s evidence of pneumonia (which is not as common as you think just because you cough a lot)
  • Complete blood count to check your white blood cells. This is usually high when you have any kind of infection, but the differential can clue you in to whether it’s bacterial or viral (another topic of discussion). This isn’t always done unless you are concerned for a serious infection like severe pneumonia, as the fact the WBCs are high doesn’t add much to the picture.
  • If there’s an underlying disease making the respiratory infection more risky, like COPD, asthma, lung diseases, etc, they may want to check other blood tests.
  • If highly suspected maybe blood tests to check for uncommon things like genetic conditions, HIV. Or mono.

Usually the only reason they would do a test is if it would change management of the condition. Often, there’s no point determining which virus it is, you’d manage it the same, except early intervention in flu, severe infections, or young kids. An elevated WBC doesn’t tell you much except “likely infection” which you already know by the clinical symptoms. Etc.

Note, ESR and CRP have low role in respiratory infections generally, unless we’re looking at sepsis from pneumonia/sinus infection, and then you’d usually add lactate and trend those.


Blood tests

What happens during a blood test?

A blood test usually involves taking a blood sample from a blood vessel in your arm.

The arm is a convenient part of the body to use because it can be easily uncovered. The usual place for a sample to be taken from is the inside of the elbow or wrist, where the veins are relatively close to the surface.

Blood samples from children are often taken from the back of the hand. Their skin may be numbed with a special spray or cream before the sample is taken.

A tight band (tourniquet) is usually put around your upper arm. This squeezes the arm, temporarily slowing down the flow of blood and causing the vein to swell. This makes it easier for a sample to be taken.

Before taking the sample, the doctor or nurse may clean the area of skin with an antiseptic wipe.

A needle attached to a syringe or special container is inserted into the vein. The syringe is used to draw out a sample of your blood. You may feel a slight pricking or scratching sensation as the needle goes in, but it shouldn’t be painful. If you don’t like needles and blood, tell the person who is taking the sample so they can make you more comfortable.

When the sample has been taken, the tourniquet will be released, and the needle will be removed. Pressure is applied to the skin for a few minutes using a cotton-wool pad. A plaster may be put on the small wound to keep it clean.

10 Things Your Doctor Won’t Tell You About Your Blood Test

2. ‘Normal’ May Differ Between Men and Women

If you compare your blood test results with those of someone of the opposite sex, you may be surprised to find differences. For example, the normal reference range for the number of red blood cells in a complete blood count is between 5 million and 6 million cells per microliter for a man, but for women, it’s between 4 million and 5 million, according to the NHLBI.

3. ‘Normal’ May or May Not Vary by Age

For some tests, such as the hemoglobin test, normal results vary by age. For children, for example, a hemoglobin level of about 11 to 13 grams/deciliter (g/dl) is normal, while for men, a value of about 14 to 17 g/dl is normal, and for women, 12 to 15 g/dl is normal. But for other tests, such as LDL cholesterol, a level less than 100 milligrams/deciliter (mg/dl) is considered optimal regardless of age. That being said, your age and other risk factors for heart disease may influence how your doctor reacts if your blood test shows a higher-than-optimal LDL cholesterol level. If you are a man over 45 or a woman over 55 and you have heart disease or diabetes, your doctor will likely advise you to take steps to lower your LDL cholesterol if it is higher than 100 mg/dl.

4. A ‘Positive’ Test Result May Not Be Positive News

Some blood tests look for diseases by searching for molecular markers in your blood sample — among them the sickle cell anemia test, the HIV test, the hepatitis C test, and the BRCA1 or BRCA2 gene test for breast and ovarian cancer risk. Results are considered “positive” when the test finds the disease marker — DNA, antibody, or protein — that it is looking for. In these cases, a positive test result means you may have the disease or disorder or, in the case of infectious diseases, that you may have been exposed to it in the past.

RELATED: 10 Cancer Screenings Every Woman Should Know About

5. A ‘Negative’ Test Result Is Usually Good News

“Negative” is not the same as “bad” when it comes to blood tests. A negative result means that the test did not detect what it was seeking, whether it was a disease marker or a risk factor for a health condition. When you’ve had a blood test to check for an infectious disease — an interferon gamma release assay for tuberculosis, for example — getting back a negative result is good news — it means the test found no evidence of an infection.

6. False-Positive Test Results Are Possible

The first screening test for a condition often has to be confirmed by a second, more specific test to find out whether the results are accurate and meaningful for your health. An example is the rapid HIV test, which is often accurate but rarely will cause a false positive (meaning the test result is positive, but the person does not actually have the disease). This can occur with certain tests that measure antibodies, since a person may have an immune condition (such as rheumatoid arthritis or multiple myeloma) that also produces antibodies and interferes with the test.

7. False-Negative Test Results Happen, Too

Sometimes a test doesn’t pick up evidence of a disease or condition, even though you actually do have it. For example, if you had a blood test for hepatitis C and the results came back negative, but you were exposed to the virus in the past few months, you could still have an infection and not realize it. Similarly, if you’re tested for Lyme disease within the first few weeks of an infection, your blood test is likely to come back negative because your body has not yet developed antibodies.

8. Test Values Can Be Different From Lab to Lab

Lab technicians’ reports compare your blood test results with a range that is considered normal for that laboratory. The lab’s reference range is based on test results from many people previously tested in that lab. This normal range may not be the same as another lab’s, notes the Food and Drug Administration, so don’t be surprised if you find that a prior blood test report varies from newer reports — the difference could be in the lab.

9. Abnormal Results May Not Be Due to a Disease

A test result outside the normal range of expected lab values does not necessarily mean you have a disease or disorder. Test results can be abnormal for other reasons. If you had a fasting plasma glucose test and you ate something before the test, or were drinking alcohol the night before or taking certain medications, your results could be temporarily outside the normal ranges, but are not evidence of a disease. To avoid such problems, it is best to talk with your doctor before any lab tests about whether you need to make any special preparations before getting your blood drawn, such as fasting the night before.

10. Mistakes Happen

Although mix-ups of blood test samples are rare, they do happen. How your blood sample is handled before it’s analyzed can affect results, too. For example, if the sample is collected in the wrong container, shaken inappropriately, or stored for too long or at the wrong temperature, you may get an erroneous result.

In this article, I’ll address a real mainstay of modern medicine: laboratory tests that require drawing blood.

This is sometimes referred to as “checking labs,” “doing bloodwork,” or even “checking blood.”

Most older adults have been through this. For instance, it’s pretty much impossible to be hospitalized without having bloodwork done, and it’s part of most emergency room care. Such testing is also often done as part of an annual exam, or “complete physical.”

Last but not least, blood testing is usually — although not always — very helpful when it comes to evaluating many common complaints that affect aging adults.

Fatigued and experiencing low energy? We should perhaps check for anemia and thyroid problems, among other things.

Confused and delirious? Bloodwork can help us check on an older person’s electrolytes (they can be thrown off by a medication side-effect, as well as by other causes). Blood tests can also provide us with information related to infection, kidney function, and much more.

Like much of medical care, blood testing is probably overused. But often, it’s an appropriate and an important part of evaluating an older person’s health care concerns. So as a geriatrician, I routinely order or recommend blood tests for older adults.

Historically, laboratory results were reviewed by the doctors and were only minimally discussed with patients and families. But today, it’s becoming more common for patients to ask questions about their results, and otherwise become more knowledgeable about this aspect of their health.

In fact, one of my top recommendations to older adults and family caregivers is to always request a copy of your laboratory results. (And then, keep it in your personal health record!)

This way, if you ever have questions about your health, or need to see a different doctor, you’ll be able to quickly access this useful information about yourself.

In this article, I’m going to list and briefly explain the blood tests that are most commonly used, for the primary medical care of older adults.

Specifically, I’ll cover four “panels” which are commonly ordered, and then I’ll list six more blood tests that I find especially useful.

In other words, we’re going to cover my top ten blood tests for the healthcare of aging adults.

I’ll finish with some practical tips for you to keep in mind, when it comes to blood tests.

4 common “panels” in laboratory blood testing

1. Complete Blood Count (CBC)

What it measures: A CBC is a collection of tests related to the cells in your blood. It usually includes the following results:

  • White blood cell count (WBCs): the number of white blood cells per microliter of blood
  • Red blood cell count (RBCs): the number of red blood cells per microliter of blood
  • Hemoglobin (Hgb): how many grams of this oxygen-carrying protein per deciliter of blood
  • Hematocrit (Hct): the fraction of blood that is made up of red blood cells
  • Mean corpuscular volume (MCV): the average size of red blood cells
  • Platelet count (Plts): how many platelets (a smaller cell involved in clotting blood) per microliter of blood

The CBC can also be ordered “with differential.” This means that the white blood cells are classified into their subtypes. For more information on the CBC test, see Medline: CBC blood test. For details on the white blood cell count differential, and what the results might signify, see Medline: Blood differential test.

What the CBC is often used for:

  • Anemia may be diagnosed if the red blood cell count, hemoglobin, and hematocrit are lower than normal.
    • I explain anemia in more depth here: Anemia in the Older Adult: 10 Common Causes & What to Ask.
  • The white blood cell count usually goes up if a person is fighting an infection. Some medications, such as corticosteroids, can also cause an increase in the white blood cell count.
  • If several types of blood cells (i.e. red blood cells, white blood cells, and platelets) are low, this can be a sign of a problem with the bone marrow.
  • Occasionally an older person’s platelet count may be lower than normal (or even higher than normal). This usually requires further evaluation.

2. Basic metabolic panel (basic electrolyte panel)

What it measures: Although it’s possible to request a measurement of a single electrolyte, it’s far more common for electrolytes to be ordered as part of a panel of seven or eight measurements. This is often referred to as a “chem-7,” and usually includes:

  • Sodium
  • Potassium
  • Chloride
  • Carbon dioxide (CO2) (sometimes referred to as “bicarbonate,” as this is the chemical form of carbon dioxide which is more common in the bloodstream)
  • Blood urea nitrogen (BUN)
  • Creatinine (often accompanied by an estimated “glomerular filtration rate,” or “eGFR”result)
  • Glucose

What the basic metabolic panel is often used for:

  • Medication side-effects can cause electrolytes such as sodium or potassium to be either too high or too low.
    • These electrolytes are often monitored when people take certain types of medications, such as certain blood pressure medications, or diuretics.
  • Carbon dioxide levels reflect the acidity of the blood.
    • This can be affected by kidney function and by lung function. Severe infection can also change acid levels in the blood.
  • Creatinine and BUN levels are most commonly used to monitor kidney function. Both of these measurements can go up if kidney function is temporarily impaired (e.g. by dehydration or a medication side-effect) or chronically impaired.
    • It is common for older adults to have at least mild decreases in kidney function.
    • Many medications must be dosed differently, if a person has decreased kidney function.
    • Laboratories now routinely use the patient’s age and creatinine level to calculate an “estimated glomerular filtration rate,” which represents the filtering power of the kidneys. This is considered a better measure of kidney function than simply relying on creatinine and BUN levels.
  • Glucose levels represent the amount of sugar in the blood.
    • If they are higher than normal, this could be due to undiagnosed diabetes or inadequately controlled diabetes.
    • If the glucose levels are on the low side, this is called hypoglycemia. It is often caused by diabetes medications, and may indicate a need to reduce the dosage of these drugs.

For more details on these tests, see Medline: Basic Metabolic Panel. From this page, you can find links to additional pages which explain each of the above electrolytes and metabolic components in detail, including common causes of the result being abnormally high or low.

3. Comprehensive metabolic panel

What it measures: This panel includes the items above in the basic metabolic panel, and then usually includes an additional seven items. For this reason, it’s sometimes referred to as a “chem-14” panel. Beyond the seven tests included the basic panel (see above), the comprehensive panel also adds:

  • Calcium
  • Total protein
  • Albumin
  • Bilirubin (total)
  • Alkaline phosphatase
  • AST (aspartate aminotransferase)
  • ALT (alanine aminotransferase)

What the comprehensive metabolic panel is often used for:

  • Calcium levels are usually regulated by the kidneys and by certain hormones.
    • Blood calcium levels are not usually a good way to assess calcium intake or total calcium stores in the bones and body.
    • High or low blood calcium levels can cause symptoms, including cognitive dysfunction, and usually indicate an underlying health problem. They can also be caused by certain types of medication.
  • Albumin is one of the key proteins in the bloodstream. It is synthesized by the liver.
    • Low albumin levels may indicate a problem with the liver or a problem maintaining albumin in the bloodstream.
    • Malnutrition may cause low albumin levels.
  • AST and ALT are enzymes contained in liver cells.
    • An elevation in these enzymes often indicates a problem affecting the liver. This can be caused by medications or by a variety of other health conditions.
  • Bilirubin is produced by the liver, and usually drains down the bile ducts and into the small intestine. Some bilirubin is also related to the breakdown of red blood cells.
    • An increase in bilirubin can be caused by gallstones or another issue blocking the bile ducts.
  • Alkaline phosphatase is found throughout the body, but especially in bile ducts and also in bone.
    • Higher levels are often caused by either a blockage in the liver or by a problem affecting bone metabolism.

For more details on these tests, and the possible causes of abnormal results, see Medline: Comprehensive Metabolic Panel.

4. Lipid (cholesterol) panel

What it measures: These tests measure the different types of cholesterol and related fats in the bloodstream. The panel usually includes:

  • Total cholesterol
  • High-density lipoprotein (HDL) cholesterol, sometimes known as “good” cholesterol
  • Triglycerides
  • Low-density lipoprotein (LDL) cholesterol, sometimes known as “bad” cholesterol
    • LDL results are usually calculated, based on the other three results

People are often asked to fast before having their cholesterol checked. This is because triglycerides can increase after eating, and this can cause a falsely low LDL to be calculated. However, experts have recently concluded that in most cases, it’s not necessary for people to fast; it’s inconvenient and only makes a small difference in test results.

What the lipid panel is often used for:

  • These tests are usually used to evaluate cardiovascular risk in older adults.
  • Higher than normal total or LDL cholesterol levels are sometimes treated with a medication, such as a statin. They can also be reduced by dietary changes (see Your Guide to Lowering Cholesterol with Therapeutic Lifestyle Changes, from the NIH).
  • For more on these tests, see Medline: Cholesterol testing and results.

6 more blood tests that I order often

Here are six other types of tests that I often order on my older patients:

1. Tests related to thyroid function

What these measure: These tests can be used to screen for thyroid disorders, or to help calibrate the dosage of thyroid replacement medications. The most commonly used tests are:

  • Thyroid stimulating hormone (TSH)
  • Free thyroxine (“free T4” or FT4)

In more complicated situations, other tests related to thyroid function may also be ordered.

What these tests are often used for:

  • Thyroid problems are common in older adults (especially older women), and are associated with symptoms such as fatigue and cognitive difficulties.
  • If an older person is having symptoms that could be related to a thyroid problem, the first step is to check the TSH level.
  • TSH usually reflects the body’s determination of whether the available thyroid hormone is sufficient or not.
    • If the thyroid gland is not making enough thyroid hormone, TSH should be higher than normal.
  • Free T4 is often used to confirm a thyroid hormone problem, if the TSH is abnormal.

For more information about thyroid problems in older adults, see Thyroid Problems. You can also read a more in-depth scholarly article here: Approach to and Treatment of Thyroid Disorders in the Elderly.

2. Tests related to vitamin B12 levels

What these measure: These measure the serum levels of vitamin B12 and provide information as to whether the level is adequate for the body’s needs. The two tests involved are:

  • Vitamin B12
  • Methylmalonic acid

Depending on the situation, if an older adult is found to have low vitamin B12 levels, additional testing may be pursued, to determine the underlying cause of this vitamin deficiency.

What these tests are often used for:

  • Vitamin B12 deficiency is quite common in older adults, and can be related to common problems such as fatigue, memory problems, and walking difficulties.
  • Methylmalonic acid levels in the body are related to vitamin B12 levels, and can help confirm a vitamin B12 deficiency.
    • It is especially important to check this, if an older person has vitamin B12 levels that are on the low side of normal.
    • Low vitamin B12 levels are associated with higher-than-normal methylmalonic acid levels
  • For more information, see: How to Avoid Harm from Vitamin B12 Deficiency.

3. Glycated hemoglobin (Hemoglobin A1C)

What it measures: Glycated hemoglobin is formed in the body when blood glucose (blood sugar) attaches to the hemoglobin in red blood cells. It is normal for glucose to do this, but if you have more glucose in the blood than normal, your percentage of glycated hemoglobin will be higher than normal. The higher one’s average blood sugar level, the greater percentage of glycated hemoglobin one will have. A result of 6.5% or above is suggestive of diabetes. For more information:

  • Hemoglobin A1C test

What this test is usually used for:

  • This test is most often ordered to monitor the blood sugar control of people with diabetes.
    • Whereas a blood glucose level (which can be checked by fingerstick or as part of a basic metabolic panel) reports the blood gluose level at a specific moment in time, a hemoglobin A1C reflects how high a person’s blood sugar has been, on average, over the prior three months.
  • A hemoglobin A1C test can also be used as part of an evaluation for possible diabetes or pre-diabetes.
  • Older adults should work with their doctors to determine what A1C goal is right for them. It is often appropriate to aim for a slightly higher goal in older adults than in younger adults. For more on this, see Diabetes Care & Treatment.

4. Prothrombin time (PT) and International Normalized Ratio (INR)

What it measures: These two tests are used as a measure of how quickly a person’s blood clots. People taking the blood-thinner warfarin (brand name Coumadin) must have this regularly monitored. For more information:

  • Prothrombin time (PT)

What this test is usually used for:

  • The INR is calculated by the laboratory, based on the prothrombin time. In people taking warfarin, the usual goal is for the INR to be between 2.0 and 3.0.
    • The most common reason older adults take warfarin is to prevent strokes related to atrial fibrillation.
    • Warfarin may also be prescribed after a person has experienced a blood clot in the legs, lungs, or elsewhere.
  • The prothrombin time is also sometimes checked if there are concerns about unexplained bleeding, severe infection, or the ability of the liver to synthesize clotting factors.

5. Brain natriuretic peptide (BNP) test

What it measures: Despite the name, BNP levels are mainly checked because they relate to heart function (not brain function!). BNP levels go up when a person’s heart cannot pump blood as effectively as it should, a problem known as “heart failure.” For more information on this test:

  • Brain natriuretic peptide (BNP) test

A related, but less commonly used, test is the “N-terminal pro-B-type natriuretic peptide” (NT-proBNP) test.

What this test is used for:

  • Checking a BNP level is mainly used to evaluate for new or worsening heart failure. This is a common chronic condition among older adults, which can occasionally get worse.
  • The BNP test can be especially useful in evaluating a person who is complaining of shortness of breath.
    • Shortness of breath can be caused by several different problems, including pneumonia, chronic obstructive pulmonary disease, pulmonary edema, angina, and much more.
    • A low BNP level means that at that moment, the shortness of breath is unlikely to be due to heart failure.
  • Checking BNP levels over time is also sometimes used to monitor a person’s heart failure and response to treatment.
  • For more about heart failure, see Heart failure tests and diagnosis and also Heart failure.

6. Ferritin

What it measures: The body’s serum ferritin level is related to iron stores in the body. For more about this test:

  • Ferritin

Depending on the situation, if an older person’s iron levels need further evaluation, additional tests can be ordered.

What this test is used for:

  • Ferritin levels are most commonly used as part of an evaluation for anemia (low red blood cell count). A low ferritin level is suggestive of iron-deficiency, which is a common cause of anemia.
    • Studies estimate that only a third of anemias in older adults are due to deficiencies in iron or other essential elements.
    • It’s important to confirm iron deficiency by checking ferritin or other tests, before relying on iron to treat an older person’s anemia.
  • Ferritin levels are also influenced by inflammation, which tends to make ferritin levels rise.
  • If the ferritin levels are borderline, or if there are other reasons to be concerned about an older person’s ability to manage iron, additional blood tests related to iron may be ordered.
  • For more on evaluating and treating anemia in older adults, see Anemia in the Older Adult: 10 Common Causes & What to Ask.

Obviously, there are many more tests that can be ordered as part of the medical care of older adults. But the tests I cover above are, by far, the ones I order the most often.

Tips to help you benefit from your blood tests and results

Here are my top tips:

1. Be sure you understand why a given test is being ordered. Is it meant to help evaluate a symptom? Monitor a chronic condition? Assess whether a treatment is working?

You will understand your own health issues better, if you ask questions about the purpose of the blood tests your doctors are proposing.

In general, blood tests should only be ordered for a reason, such as to evaluate a concerning symptom, to monitor a chronic disease, or to check for certain types of medication side-effect.

Keep in mind that it’s only occasionally appropriate to order blood tests for “screening.” A screening test means a person doesn’t have any symptoms. Such screening blood tests are only recommended for a handful of conditions.

For more on preventive health care and screening tests that may be appropriate for older adults, see 26 Recommended Preventive Health Services for Older Adults.

2. Ask your doctor to review the results and explain what they mean for your health. Try to look at the report with your doctor. It’s especially important to ask about any result that is flagged as abnormal by the laboratory system.

For instance, I have found that many older adults are unaware of the fact that they have mild or moderate kidney dysfunction, even though this has been evident in prior laboratory tests. This happens when people do not review reports and ask enough questions.

Wondering why the doctor wouldn’t tell an older person that the kidney function is abnormal?

Well, if it’s been going on for a while, the doctor might think the older person already knows about this issue. Or perhaps the doctor mentioned it before, but the older person didn’t quite hear it. It’s also not uncommon for doctors to just not get around to mentioning a mild abnormality that is pretty common in older people, such as mild anemia or mild kidney dysfunction.

3. Ask your doctor to explain how your results compare with your prior results. Laboratory reports will always provide a “normal” reference range. But what’s usually more useful is to see how a given result compares to your previous results.

For instance, if an older person’s complete blood count (CBC) shows signs of anemia, it’s very important to look at prior CBC results. This helps us determine what the “trajectory” of the blood count is. A blood count that is drifting down — or worse yet, dropping fairly suddenly — is much more concerning than one that has been lower-than-normal, but stable for the past year. Ditto test results suggesting diminished kidney function, and for many other abnormal blood test results.

Of course, you’ll want to understand what might be the cause of an abnormal result regardless of the trajectory. But a worsening blood test result usually means the issue is more urgent to sort out.

4. Request copies of your results, and keep them in your own record system. Past laboratory results provide incredibly useful information to health providers, and can be very useful to you as well.

If you keep your own copies of results, you’ll be better able to:

  • Share them with new doctors, if you change health providers, move to a new city, or have to go to the emergency room.
  • Research your health condition, in order to better understand it and know what questions to ask your doctor.

For instance, one of my family members recently had a “routine” cholesterol panel done. He takes no medications, is quite fit, and is in good health, so he was surprised when some of his results came back higher than normal. We promptly reviewed his previous results, from three years ago, and found that those results were within normal range. So this family member is now in the process of reconsidering his diet.

If he hadn’t had copies of his previous labs, he could have asked his doctor. But it’s much faster and more convenient to be able to look in your own records!

And don’t just rely on looking up past results through a patient portal. Clinics will often remove your access, if you are deemed to have left the practice. So it is very important to keep your own copies of results.

For more on the benefits of maintaining your own personal health record — or a health record for an older parent — see How to Use a Personal Health Record to Improve an Older Person’s Healthcare.

Do you have questions about common blood tests for older adults? Please post them below and I will do my best to address them.

All About Blood Tests

Let’s take a closer look at tests for adults to have done regularly.

1. Complete blood count

A routine complete blood count (CBC) test checks for levels of 10 different components of every major cell in your blood: white blood cells, red blood cells, and platelets. Important components measured by this test include red blood cell count, hemoglobin, and hematocrit.

Here’s the typical range of results:

Abnormal levels of these components may indicate:

  • nutritional deficiencies, such as vitamin B-6 or B-12
  • iron deficiency
  • bone marrow issues
  • tissue inflammation
  • infection
  • heart conditions
  • cancer

Based on your results, your doctor will order follow-up tests to confirm abnormal levels and a possible diagnosis.

2. Basic metabolic panel

A basic metabolic panel (BMP) checks for levels of certain compounds in the blood, such as:

  • electrolytes
  • calcium
  • glucose
  • sodium
  • potassium
  • carbon dioxide
  • chloride
  • blood urea nitrogen (BUN)
  • creatinine

This test requires you to fast for at least eight hours before your blood is drawn.

See our chart for normal results.

Abnormal results may indicate kidney disease, diabetes, or hormone imbalances. Your doctor will perform follow-up tests to diagnose any of these conditions.

3. Complete metabolic panel

A complete metabolic panel (CMP) includes all the measurements of a BMP as well as additional proteins and substances related to liver function:

  • albumin
  • total protein
  • alkaline phosphatase (ALP)
  • alanine aminotransferase (ALT)
  • aspartate aminotransferase (AST)
  • bilirubin

The same conclusions can be drawn from a CMP as from a BMP for the same substances that a BMP covers. Other abnormal levels can also indicate underlying conditions, such as:

High levels Low levels
ALP • bile duct blockage
• cirrhosis
• gallbladder inflammation
• gallstones
• hepatitis
• Paget’s disease
• bone metabolism disorders
• heart surgery
• malnourish
• mentzinc deficiency
ALT • cirrhosis
• hepatitis
• liver cancer
• liver damage
considered normal
AST • cirrhosis
• heart conditions
• hepatitis
• mononucleosis
• (mono)pancreatitis
considered normal
Bilirubin • abnormal red blood cell destruction (hemolysis)
• adverse medication reactions
• bile duct blockage
• Gilbert’s syndrome
• hepatitis
not a concern

4. Lipid panel

This test checks levels of two types of cholesterol:

  • high-density lipoprotein (HDL), or “good” cholesterol
  • low-density lipoprotein (LDL), or “bad” cholesterol

HDL is “good” because it removes harmful substances from your blood and helps the liver break them down into waste. LDL is “bad” because it can cause plaque to develop in your arteries, increasing your risk of heart disease.

You need to fast for at least 8 hours before this test.

Here are the ranges for each type:

High Low
HDL > 60 mg/dL men: < 40 mg/dL; women: < 50 mg/dL
LDL > 160 mg/dL < 100 mg/dL

Normal levels can also vary by age.

5. Thyroid panel

A thyroid panel, or thyroid function test, checks how well your thyroid is producing and reacting to certain hormones, such as:

  • Triiodothyronine (T3). Along with T4, this regulates your heart rate and body temperature.
  • T3 resin uptake (RU). This measures how well a hormone called thyroxin-binding globulin is binding.
  • Thyroxine (T4). Along with T3, this regulates your metabolism and how you grow.
  • Thyroid-stimulating hormone (TSH). This helps regulate the levels of hormones your thyroid releases.

Your thyroid, a tiny gland in your neck, helps regulate bodily functions like your mood, energy level, and overall metabolism.

Here are normal results:

Abnormal levels of these hormones can indicate numerous conditions, such as low protein levels, thyroid growth disorders, and abnormal levels of testosterone or estrogen.

6. Enzyme markers

Enzymes are proteins that help your body accomplish certain chemical processes, such as breaking down food and clotting blood. They’re used throughout your body for many vital functions. Abnormal enzyme levels can indicate many different conditions.

Common enzymes tested include:

  • Creatine phosphokinase (CPK-1). This is found in your lungs and brain. High levels can indicate brain injuries or cancer.
  • CPK-2 (CK-MB). These enzymes are found in your heart. They often increase in your blood after a heart attack or other heart injury.
  • CPK-3. These enzymes are also found in your heart. They often result from muscle inflammation, injury, or intense exercise.
  • Troponin. This is a heart enzyme that can leak into your blood and results from heart injury.

Here are the normal ranges for the enzyme listed above:

  • CPK-1:about 200 units per liter (U/L)
  • CPK-2:5–25 international units per liter (IU/L)
  • CPK-3:about 200 U/L
  • troponin:< 0.02 ng/mL

7. Sexually transmitted disease tests

Many sexually transmitted diseases (STDs) can be diagnosed using a blood sample. These tests are often combined with urine samples or swabs of infected tissue for more accurate diagnoses.

The following STDs can be diagnosed with blood tests:

  • chlamydia
  • gonorrhea
  • herpes
  • HIV
  • syphilis

Blood tests aren’t always accurate right after contracting an infection. For an HIV infection, for example, you may need to wait at least a month before a blood test can detect the virus.

8. Coagulation panel

Coagulation tests measure how well your blood clots and how long it takes for your blood to clot. Examples include the prothrombin time (PT) test and fibrinogen activity test.

Clotting is a crucial process that helps your stop bleeding after a cut or wound. But a clot in a vein or artery can be deadly, blocking blood flow to your brain, heart, or lungs and causing heart attack or strokes.

Coagulation test results vary based on your health and any underlying conditions that may affect clotting.

Results from this test can be used to diagnose:

  • acute myeloid leukemia
  • excessive bleeding (hemophilia)
  • thrombosis
  • liver conditions
  • vitamin K deficiency

9. DHEA-sulfate serum test

The dehydroepiandrosterone (DHEA) hormone comes from your adrenal glands. This test measures whether it’s too high or too low.

In men, DHEA helps develop traits like body hair growth, so low levels are considered abnormal. In women, high levels can cause typically male traits, like excess body hair, to develop, so low levels are normal.

Low levels in men are called DHEA deficiency, which can be caused by:

  • type 2 diabetes
  • kidney disease
  • anorexia nervosa
  • AIDS

High levels in men or women can result from:

  • cancer or tumor in adrenal glands
  • early onset of puberty from congenital adrenal hyperplasia
  • abnormal genital development
  • polycystic ovary syndrome (in women)

10. C-reactive protein test

C-reactive protein (CRP) is made by your liver when tissues in your body are inflamed. High CRP levels indicate inflammation from a variety of causes, including:

  • artery inflammation
  • infection
  • inflammatory bowel disease (IBD)
  • heart disease
  • rheumatoid arthritis
  • lupus
  • cancer

The higher the level in your results, the higher your risk of heart disease:

  • < 1 mg/L: low risk
  • 1–2.9 mg/L: intermediate risk
  • > 3 mg/L: high risk
  • > 10 mg/L: extremely high risk, and further testing should be done to diagnose high levels of inflammation in your body

What Are the Most Important Types of Blood Tests You Should Have?

Your blood can tell a doctor so much about your health. Depending on your age, gender, symptoms and any health conditions you may have, your doctor will choose specific types of blood tests to help determine how best to care for you. Even though no two patients are the same, there are several recommended blood tests that are common and important for everyone to get.

Complete Blood Count (CBC) Test

This complete blood count test is one of the most common blood tests done. It’s low cost and gives doctors a lot of diagnostic information. It gives physicians and other healthcare professionals a quick overview of things like how well your immune system is working, how well oxygen is circulating throughout your body, and how well your body can stop a cut from bleeding.

Comprehensive Metabolic Panel (CMP)

A comprehensive metabolic panel gives doctors insight into how well things like your lungs, kidneys, and liver are working. Electrolytes like potassium, calcium, and sodium are measured. It also tests blood glucose, which is important when detecting early-stage metabolic syndrome, diabetes, and coronary artery disease. That makes it an excellent indicator of nutritional deficiencies, and it also works hand-in-hand with a CBC to help detect problems like dehydration.

Thyroid Stimulating Hormone (TSH) Test

A healthy thyroid is key to good metabolism. Yet thyroid problems are often hard to diagnose because there is no single symptom or test that can determine the issue, but a thyroid stimulation hormone level test is a good place to start. By measuring the level of TSH in your blood, your doctor can see whether the amount of this hormone your thyroid secretes is too high, too low, or just right. The level of TSH in your blood shows how well your thyroid is functioning and whether your metabolism is working too fast or too slow, causing symptoms like mood swings and abnormal heart rhythms.

Lipid Panel Tests

Lipid panel tests require fasting for eight to 12 hours and determines your risk of heart disease. It measures your total cholesterol, LDL (“bad”) cholesterol, HDL (“good”) cholesterol, and triglycerides.

Blood glucose Test

A blood glucose test requires fasting and measures the amount of a sugar — in this case glucose — that is stored in your body. It looks at how efficient your body is managing sugar. This test helps your doctor determine if you have diabetes.

Did you know your blood could reveal all that? If you’re interested in the human body, a healthcare career might be a good fit for you. Check out the medical assistant program or any of the other health care programs at Charter College today to learn more.

5 Essential Blood Tests You Need Every Year

Blood work and advanced medical testing can catch issues before they become a problem. That’s why there are a few key labs you should have done each year.

Most people who have been to a primary care doctor in the past have been told, “All your blood tests looks normal. Keep on doing what you’re doing.” They might even say this to you despite your physical, mental, or emotional complaints. What they really mean is, “Keep on doing what you’re doing, until something is so wrong with you that even your basic labs look abnormal, and then I can prescribe you a toxic drug.”

Unfortunately, our current medical system does not put enough monetary value toward the prevention of disease. It does not financially incentivize doctors to talk with their patients about their lifestyle habits or order extensive labs which could catch underlying dysfunction early enough to prevent full-blown illness.

Why Annual Blood Testing is Important

At Parsley Health, we do exactly that. Members’ first visits are 75 minutes, so we get to know their entire life story. We order many advanced blood tests and we spend another 60 minutes with members going through every little detail. Then, we use that information to advise members’ care. Throughout the year, we follow the pertinent blood values to ensure members are optimizing their health.

Parsley’s medical plans include personalized testing to help you identify nutrient deficiencies. Join Parsley today.

The 5 types of blood tests you should do every year

1. Broad Thyroid Panel

In most primary care offices, if you’re lucky, your doctor will check 1 or 2 thyroid markers. Usually, the ones checked are TSH and/or total T4. These give you a little glimpse as to how the thyroid is functioning. There are 6 additional thyroid-related values that we routinely check for our patients: Free T4, Total T3, Free T3, Reverse T3, anti TPO Ab and anti Thyroglobluin Ab. If any of these blood tests values are not optimal, we can start our patients on a program to prevent full-blown thyroid dysfunction or disease.

We look for “optimal ranges” as opposed to “normal ranges” of these labs. For example, the “normal range” for TSH is generally considered 0.2 – 4.5, however, there are studies that show that the body does not function properly when TSH rises above 2.5. A study published in the Journal of Endocrinology and Metabolism in 2010 even showed that the rate of miscarriage in first trimester pregnancy was almost double when the TSH was over 2.5.

2. Essential Nutrients: iron/ferritin, vitamin D, vitamin B12, magnesium

Iron, vitamin D, vitamin B12, and magnesium are so important for optimal bodily function, but they’re usually not checked at a routine primary care visit. Many people are deficient in these nutrients for various reasons, so it is imperative that we check these levels and supplement them when they are not optimal. Supplementation with any of these nutrients when people are low can be completely life-altering. I’ve had countless patients tell me how seemingly magical the improvement was in how they felt after taking these supplements when it was needed.

Again, it’s important that we concern ourselves with getting to “optimal range” as opposed to “normal range”. For example, in the case of vitamin D, the “normal range” can be from 30-100 nmol/l, although we try to get our patients in “optimal range” which is more like 50-80 nmol/l. Reviews of many scientific studies have shown optimal levels are at least 75 nmol/l in relation to bone mineral density (BMD), lower extremity function, dental health, risk of falls, admission to nursing home, fractures, cancer prevention, and incident hypertension.

3. Complete Metabolic Panel and Complete Blood Count

These are two blood tests that are always ordered at a primary care yearly physical and offer a lot of information. They are essential to understanding a person’s electrolyte and hydration status, kidney function, liver function, and blood cell values. These values would also tell us if someone is fighting an acute or chronic infection, has anemia, or clotting issues.

In terms of optimal ranges, when we look at liver enzyme levels that are still considered in “normal range”, but on the upper end, we can tell that there might be a detoxification or liver inflammation issue that should be addressed right away to prevent further progression of illness. A number of studies have shown that this upper lab limit should be decreased in order to catch liver inflammation early, especially among certain ethnic populations.

4. Metabolic Markers: Hemoglobin A1c, fasting glucose and insulin, lipid panel

Metabolic markers like these are essential to understanding how a person is processing the macronutrients that they eat. In most primary care visits, a basic lipid panel and glucose level would be done yearly, and if you’re lucky you’ll also get a Hemoglobin A1c. For patients at higher risk of heart disease, we run extensive lipid panels as opposed to a basic one. This can help us better determine whether there is actually increased heart disease risk from their cholesterol levels or not. Many times people are told that they have high cholesterol levels when they are not actually a risk.

The Hba1c is a measurement of blood glucose level average over the past 90 days or so, but it is also a relative marker of oxidation in the body. Having elevated blood glucose levels creates oxidation, or damage to proteins, DNA, and tissues in our bodies over time, so this is an imperative value to know and optimize.

Elevations in any of these levels are a sign that your body is not processing glucose properly, which can increase your risk for diabetes, heart disease, cancer, and Alzheimer’s disease. One study published in the Journal of Neurology in 2005 (6) showed that even if your Hba1c is considered in “normal range”, every increase by 0.1 will increase the rate at which your brain shrinks in size per year. This is why being advised on how to reach “optimal range” is so much more important than simply saying you’re in “normal range”.

5. Inflammatory markers: hsCRP, homocysteine

Inflammatory markers like these are almost never checked at a routine primary care visit. hsCRP is an inflammatory marker which can indicate your the general inflammatory status. Even mild increases in hsCRP are associated with increased risk of things like cardiac events or depression. An elevation can tell us that there is something inflammatory happening in the body that should be addressed, whether it be from physical trauma, emotional stress, oxidative stress, environmental toxicity, allergy, sedentary lifestyle, or food sensitivities.

Homocysteine is an amino acid that requires methylated-vitamin B12 and folate to be cleared. Elevations in this level indicate a multitude of things like stroke and heart disease risk, B vitamin status, ability to methylate, ability to detox and make neurotransmitters, and ability to turn off cancer genes. It’s an important marker that we try to get into optimal range by supplementing with methyl-B vitamins when necessary.

Work with Parsley and get a personalized testing panel that matches your specific symptoms and health goals.

Final thoughts

Having blood tests done is not what’s essential to your health. The importance is in the interpretation and advice that you get from your doctor and how that translates into actual changes in your life that will affect your health. The distinction of what the doctors do at Parsley Health is that we are interested in our patients having optimal levels in every value that we check so that their health and function are optimized.

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