Daily blood sugar level

Understanding blood glucose level ranges can be a key part of diabetes self-management.

This page states ‘normal’ blood sugar ranges and blood sugar ranges for adults and children with type 1 diabetes, type 2 diabetes and blood sugar ranges to determine people with diabetes.

If a person with diabetes has a meter, test strips and is testing, it’s important to know what the blood glucose level means.

Recommended blood glucose levels have a degree of interpretation for every individual and you should discuss this with your healthcare team.

In addition, women may be set target blood sugar levels during pregnancy

The following ranges are guidelines provided by the National Institute for Clinical Excellence (NICE) but each individual’s target range should be agreed by their doctor or diabetic consultant.


Recommended target blood glucose level ranges

The NICE recommended target blood glucose levels are stated below for adults with type 1 diabetes, type 2 diabetes and children with type 1 diabetes.

In addition, the International Diabetes Federation’s target ranges for people without diabetes is stated.

The table provides general guidance. An individual target set by your healthcare team is the one you should aim for.

NICE recommended target blood glucose level ranges

Target Levels
by Type
Upon waking Before meals
(pre prandial)
At least 90 minutes after meals
(post prandial)
Non-diabetic* 4.0 to 5.9 mmol/L under 7.8 mmol/L
Type 2 diabetes 4 to 7 mmol/L under 8.5 mmol/L
Type 1 diabetes 5 to 7 mmol/L 4 to 7 mmol/L 5 to 9 mmol/L
Children w/ type 1 diabetes 4 to 7 mmol/L 4 to 7 mmol/L 5 to 9 mmol/L

*The non-diabetic figures are provided for information but are not part of NICE guidelines.

Normal and diabetic blood sugar ranges

For the majority of healthy individuals, normal blood sugar levels are as follows:

  • Between 4.0 to 5.4 mmol/L (72 to 99 mg/dL) when fasting
  • Up to 7.8 mmol/L (140 mg/dL) 2 hours after eating

For people with diabetes, blood sugar level targets are as follows:

  • Before meals : 4 to 7 mmol/L for people with type 1 or type 2 diabetes
  • After meals : under 9 mmol/L for people with type 1 diabetes and under 8.5mmol/L for people with type 2 diabetes

Blood sugar levels in diagnosing diabetes

The following table lays out criteria for diagnoses of diabetes and prediabetes.

Blood sugar levels in diagnosing diabetes

Plasma glucose test Normal Prediabetes Diabetes
Random Below 11.1 mmol/l
Below 200 mg/dl
N/A 11.1 mmol/l or more
200 mg/dl or more
Fasting Below 5.5 mmol/l
Below 100 mg/dl
5.5 to 6.9 mmol/l
100 to 125 mg/dl
7.0 mmol/l or more
126 mg/dl or more
2 hour post-prandial Below 7.8 mmol/l
Below 140 mg/dl
7.8 to 11.0 mmol/l
140 to 199 mg/dl
11.1 mmol/l or more
200 mg/dl or more

Random plasma glucose test

A blood sample for a random plasma glucose test can be taken at any time. This doesn’t require as much planning and is therefore used in the diagnosis of type 1 diabetes when time is of the essence.

Fasting plasma glucose test

A fasting plasma glucose test is taken after at least eight hours of fasting and is therefore usually taken in the morning.

The NICE guidelines regard a fasting plasma glucose result of 5.5 to 6.9 mmol/l as putting someone at higher risk of developing type 2 diabetes, particularly when accompanied by other risk factors for type 2 diabetes.

Oral Glucose Tolerance Test (OGTT)

An oral glucose tolerance test involves first taking a fasting sample of blood and then taking a very sweet drink containing 75g of glucose.

After having this drink you need to stay at rest until a further blood sample is taken after 2 hours.

HbA1c test for diabetes diagnosis

An HbA1c test does not directly measure the level of blood glucose, however, the result of the test is influenced by how high or low your blood glucose levels have tended to be over a period of 2 to 3 months.

Indications of diabetes or prediabetes are given under the following conditions:

  • Normal: Below 42 mmol/mol (6.0%)
  • Prediabetes: 42 to 47 mmol/mol (6.0 to 6.4%)
  • Diabetes: 48 mmol/mol (6.5% or over)


There are two types of blood sugar levels that may be measured. The first is the blood glucose level we get from doing finger prick blood glucose tests. These give us a reading of how high our levels are at that very point in time.

The second is the HbA1c reading, which gives a good idea of our average control over a period of 2 to 3 months. The target blood glucose levels vary a little bit depending on your type of diabetes and between adults and children.

Where possible, try to achieve levels of between 4 and 7 mmol/L before meals and under 8.5 mmol/L after meals. The target level for HbA1c is under 48 mmol/mol (or 6.5% in the old units).

Research has shown that high blood glucose levels over time can lead to organ and circulation damage.

By monitoring blood glucose levels, we can spot when sugar levels are running high and can then take appropriate action to reduce them.

Keeping blood glucose above 4 mmol/l for people on insulin or certain medications for type 2 diabetes is important to prevent hypos occurring, which can be dangerous.

Your doctor may give you different targets. Children, older people and those at particular risk of hypoglycemia may be given wider targets.

Download a FREE blood glucose level chart for your phone, desktop or as a printout.

Why are good blood sugar levels important?

It is important that you control your blood glucose levels as well as you can as too high sugar levels for long periods of time increases the risk of diabetes complications developing.

Diabetes complications are health problems which include:

  • Kidney disease
  • Nerve damage
  • Retinal disease
  • Heart disease
  • Stroke

This list of problems may look scary but the main point to note is that the risk of these problems can be minimised through good blood glucose level control. Small improvements can make a big difference if you stay dedicated and maintain those improvements over most days.

Normal and diabetic blood sugar ranges

This blood sugar chart shows normal blood glucose levels before and after meals and recommended HbA1c levels for people with and without diabetes.

Normal for person without diabetes 70–99 mg/dl (3.9–5.5 mmol/L)
Official ADA recommendation for someone with diabetes 80–130 mg/dl (4.4–7.2 mmol/L)
1 to 2 hours after meals
Normal for person without diabetes Less than 140 mg/dl (7.8 mmol/L)
Official ADA recommendation for someone with diabetes Less than 180 mg/dl (10.0 mmol/L)
Normal for person without diabetes Less than 5.7%
Official ADA recommendation for someone with diabetes Less than 7.0%

Source: American Diabetes Association

Fasting blood sugar

A fasting blood sugar (sometimes called fasting plasma glucose or FPG) is a blood sugar that is measured after fasting (not eating or drinking anything, except water) for at least 8 hours. The purpose of doing a fasting blood sugar test is to determine how much glucose (sugar) is in the blood, and this test is commonly used to check for diabetes or prediabetes. The blood test is usually measured at a lab, at the doctor’s office or at a hospital. A blood sample may be drawn from a vein in your arm and collected in a tube which will then be analyzed by a lab. Or, a blood sample may be obtained by doing a fingerstick with a lancet.

Normal fasting blood sugar for person without diabetes

A normal fasting blood glucose for someone who does not have diabetes ranges from 70 to 99 mg/dl. The American Diabetes Association recommends a routine screening for type 2 diabetes starting at age 45. If the results are normal, the screening should be repeated every 3 years.

If have diabetes risk factors, which include being overweight or obese, having a family history of type 2 diabetes, having a history of gestational diabetes, or being of a certain race/ethnicity (African American, Latino, Asian American, Pacific Islander, or Native American), you should be screened for diabetes sooner than age 45.

Children and adolescents who have diabetes symptoms or who are overweight and have a family history of type 2 diabetes, are of African American, Latino, Asian American, Native American or Pacific Islander descent, who have signs of prediabetes (acanthosis nigricans, high blood pressure, high cholesterol) or a mother who had gestational diabetes should be tested beginning at age 10 and then every 3 years thereafter.

A fasting blood sugar of 100 to 125 mg/dl is indicative of prediabetes, which is a condition where blood sugar levels are above “normal” but not high enough to be considered diabetes. Prediabetes is a risk factor for type 2 diabetes, heart disease and stroke. It’s managed by lifestyle changes and, in some cases, medication.

Official fasting blood sugar ADA recommendation for someone with diabetes

The American Diabetes Association recommends a fasting blood sugar target of 80 to 130 mg/dl for most nonpregnant adults with diabetes. However, the fasting blood sugar target may need to be individualized for certain people based on such factors as duration of diabetes, age and life expectancy, cognitive status, other health conditions, cardiovascular complications and hypoglycemia unawareness. It’s important that people with diabetes discuss their target blood sugar goals with their health-care provider.

What’s a normal blood sugar after eating?

After-meal blood sugar for someone without diabetes

A normal blood sugar is lower than 140 mg/dl. A blood sugar between 140 and 199 mg/dl is considered to be prediabetes, and a blood sugar of 200 mg/dl or higher can indicate diabetes. Someone who does not have diabetes is unlikely to be checking their blood sugars. However, one of the screening tests for diabetes is called an oral glucose tolerance test, or OGTT. (A slightly different version of the OGTT is also used to diagnose gestational diabetes, which is diabetes that develops during pregnancy). For this test, the person needs to fast overnight and go to the doctor’s office or a lab in the morning. A blood sample will be used to measure the fasting blood sugar. The person then drinks a sugary drink that contains 75 grams of sugar. Two hours later, blood sugar is checked again.

Normal blood sugar levels after eating for diabetics

The American Diabetes Association recommends that the blood sugar 1 to 2 hours after the beginning of a meal be less than 180 mg/dl for most nonpregnant adults with diabetes. This is typically the peak, or highest, blood sugar level in someone with diabetes. Again, this target may need to be individualized for certain people based on such factors as duration of diabetes, age and life expectancy, cognitive status, other health conditions, cardiovascular complications and hypoglycemia unawareness. It’s important that people with diabetes discuss their target blood sugar goals with their health-care provider.


The HbA1C test is a blood test that provides average levels of blood glucose over the past 3 months. Other names for this test are hemoglobin A1C, A1C, glycated hemoglobin, and glycosylated hemoglobin test. A person does not need to fast before having their HbA1C test measured; in other words, it’s OK to eat or drink something beforehand. The HbA1C test may not be accurate for some people, including those with anemias and for those receiving treatment for HIV, and for people of African, Mediterranean or Southeast Asian descent. The HbA1C result is reported as a percentage; the higher the percentage, the higher the blood sugar level.

In addition to being a tool for diagnosing diabetes, the HbA1C test is used to help people who have diabetes manage their condition.

Normal HbA1c for person without diabetes

For someone who does not have diabetes, a normal HbA1C level is below 5.7%. An A1C between 5.7% to 6.4% is indicative of prediabetes.

It’s recommended that adults over the age of 45 — or adults under 45 who are overweight and have one or more risk factors for diabetes — have a baseline A1C checked. If the result is normal, the A1C should be checked every 3 years. If the result indicates prediabetes, the A1C should be checked every 1 to 2 years.

Official HbA1c ADA recommendation for someone with diabetes

The American Diabetes Association recommends an HbA1C of less than 7% for most nonpregnant adults with diabetes. A lower goal, such as less than 6.5%, may be appropriate for some people who have had diabetes for a shorter amount of time, for younger people, for those without heart disease and/or for those with type 2 diabetes treated with lifestyle or metformin only. A higher HbA1C goal, such as less than 8%, may be appropriate for people with a history of severe hypoglycemia, a limited life expectancy, advanced diabetes complications, other illnesses, or for whom a lower HbA1C goal is difficult to achieve. It’s important that people with diabetes discuss their target blood sugar goals with their health-care provider.

HbA1C levels should be checked between 2 to 4 times per year in people who have diabetes.

Blood sugar chart: summary

The fasting blood sugar, 2-hour post-meal blood sugar and HbA1C tests are important ways to diagnose prediabetes and diabetes, as well as indicate how well a person’s diabetes is being managed. If you think you have diabetes, it’s important to not try and diagnose yourself by doing a fingerstick with a home blood glucose meter. There are strict standards and procedures that laboratories use for diagnosing diabetes; therefore, you should get tested at your doctor’s office or at a laboratory.

It’s also important to talk with your doctor to make sure you understand a) how often you should have certain tests, such as a fasting blood glucose or HbA1C test; b) what your results mean; and c) what your blood sugar and HbA1C targets are.

If you have not been previously diagnosed with prediabetes or diabetes but your results are above “normal,” your doctor may recommend other tests and should discuss a plan of treatment with you. Treatment may include lifestyle changes, such as weight loss, a healthy eating plan and regular physical activity. You may need to start taking diabetes medications, including insulin. If you are diagnosed with diabetes, it’s recommended that you learn how to check your blood sugars with a meter so that you and your healthcare team can determine how your treatment plan is working for you.

En Español: Tabla del Nivel de Azúcar en la Sangre: ¿Cuál es el Rango Normal Para el Nivel de Azúcar en la Sangre?

Interested in learning more? Read about normal blood glucose numbers, getting tested for Type 2 diabetes and using blood sugar monitoring to manage diabetes.

Amy Campbell, MS, RD, LDN, CDE

A Registered Dietitian and Certified Diabetes Educator at Good Measures, LLC, where she is a CDE manager for a virtual diabetes program. Campbell is the author of Staying Healthy with Diabetes: Nutrition & Meal Planning, a co-author of 16 Myths of a Diabetic Diet, and has written for publications including Diabetes Self-Management, Diabetes Spectrum, Clinical Diabetes, the Diabetes Research & Wellness Foundation’s newsletter, DiabeticConnect.com, and CDiabetes.com

Controlling blood sugar in diabetes: How low should you go?

Published: January, 2011

Diabetes is an ancient disease, but the first effective drug therapy was not available until 1922, when insulin revolutionized the management of the disorder. Insulin is administered by injection, but treatment took another great leap forward in 1956, when the first oral diabetic drug was introduced. Since then, dozens of new medications have been developed, but scientists are still learning how best to use them. And new studies are prompting doctors to re-examine a fundamental therapeutic question: what level of blood sugar is best?

Normal metabolism

To understand diabetes, you should first understand how your body handles glucose, the sugar that fuels your metabolism. After you eat, your digestive tract breaks down carbohydrates into simple sugars that are small enough to be absorbed into your bloodstream. Glucose is far and away the most important of these sugars, and it’s an indispensable source of energy for your body’s cells. But to provide that energy, it must travel from your blood into your cells.

Insulin is the hormone that unlocks the door to your cells. When your blood glucose levels rise after a meal, the beta cells of your pancreas spring into action, pouring insulin into your blood. If you produce enough insulin and your cells respond normally, your blood sugar level drops as glucose enters the cells, where it is burned for energy or stored for future use in your liver as glycogen. Insulin also helps your body turn amino acids into proteins and fatty acids into body fat. The net effect is to allow your body to turn food into energy and to store excess energy to keep your engine running if fuel becomes scarce in the future.

A diabetes primer

Diabetes is a single name for a group of disorders. All forms of the disease develop when the pancreas is unable to supply enough insulin to meet the body’s needs. In some cases, the problem is a low supply, in others, the body resists the insulin it has, and in still others, it’s both a low supply and insulin resistance.

Type 1 diabetes usually begins abruptly before the age of 20, often with a critical rise in blood sugar levels. The disease is caused by a combination of genetic abnormalities and environmental triggers that cause the body’s immune system to attack the pancreas, destroying its ability to produce insulin. Since insulin is required for glucose to enter cells, blood sugar levels rise sharply. Type 1 diabetes is the most severe form of the disease, but it accounts for only about 5% of cases in the United States. Lifelong insulin therapy is mandatory.

Type 2 diabetes was once called adult-onset diabetes because it usually begins gradually in adulthood. But with the alarming rise in childhood obesity, the disease is increasingly common in children and adolescents. In most cases, the main problem is insulin resistance. The pancreas produces reasonable amounts of the hormone, but the body’s tissues don’t respond properly, so blood sugar levels are abnormally high. Oral medications can help many patients compensate for insulin resistance. But over time, the ability of the overtaxed pancreas to secrete insulin may run down, creating the need for insulin therapy.

Mild elevations of blood sugar don’t produce any symptoms, which is why about a fourth of all diabetics don’t know they have the disease. When sugar levels get higher, they may produce fatigue, blurred vision, excess urination, and excessive thirst. Increased hunger is another symptom, but weight loss may develop despite a hearty appetite. This happens because while the blood has too much sugar, the cells don’t get enough. Diabetes is starvation in the midst of plenty.

Extremely high blood sugar readings can lead to dehydration, widespread metabolic abnormalities, coma, and death, conditions called diabetic ketoacidosis and hyperosmolar non-ketotic coma. Insulin therapy has made these uncommon, but diabetics are still at risk for many complications of the disease. In broad terms, these problems can be divided into two groups:

  • Microvascular complications involve small blood vessels in the kidneys, eyes, and nerves. These abnormalities explain why diabetes is a leading cause of kidney failure, blindness, and nerve damage.

  • Macrovascular complications involve larger blood vessels in the heart, brain, and legs. These abnormalities explain why diabetes is a major cause of heart attack, stroke, and leg amputations.

Many diabetics suffer from both microvascular and macrovascular complications. A particular worry for men who have diabetes is erectile dysfunction, which often develops from the combination of nerve and blood vessel damage.

The widespread organ damage produced by diabetes accounts for its dubious distinction as the seventh leading cause of death in the United States. And the disease also causes long-term distress and disability.

Do you have diabetes?

The American Diabetes Association (ADA) recommends testing for diabetes every three years for people ages 45 and older. Individuals with risk factors such as being overweight, having a diabetic parent or sibling, or having high blood pressure or high cholesterol levels should begin testing earlier and should have repeat tests as often as yearly. Although several diagnostic tests are available, two are most useful.

Fasting blood sugar (FBS). It’s the simplest, most widely used test, requiring only a single blood sample that is obtained after at least eight hours without caloric intake (see chart).

Glycosylated hemoglobin (HbA1C). This test measures the percent of your red blood cells’ oxygen-carrying hemoglobin molecules that have glucose attached to them. A normal value is below 5.7%, meaning that around 5% of hemoglobin molecules have glucose attached to them. At higher levels, glycosylation impairs function. Unlike the FBS, this test does not require fasting or any other dietary changes. Another advantage of this newer test is that it reflects a person’s average blood sugar level over the preceding two to three months, while a blood sugar test provides more of a minute-to-minute snapshot.

Beginning in 2010, the ADA gave these tests equal status for the diagnosis of diabetes.

Blood sugar control: Tightening up

Everyone likes to be normal. Quite aside from this natural human impulse, there were good reasons for scientists to assume that lowering blood sugar levels to nearly normal would reduce the risk of complications and extend the lives of patients with diabetes.

Several observations lent weight to this strategy of so-called tight blood sugar control, or intensive therapy. First, scientists believe that high blood sugar levels actually damage blood vessels over time, both directly and indirectly. When levels are high, glucose will stick to proteins, cell structures, blood fats, and platelets. Like the hemoglobin in red blood cells, the target molecules become glycosylated, which impairs their function. Proteins stick together and the membranes around small arteries thicken, so less oxygen reaches the tissues and waste products build up. The result is organ damage, which progresses slowly and steadily if blood sugar levels stay high.

Second, studies from the 1970s onward suggest that even within the “normal” range, higher blood sugar and HbA1C levels predict a higher risk of cardiovascular disease. Third, a study of 4,662 men found that blood sugar levels were directly linked to the death rate, both in men with and without diabetes; in all, a 1% percent rise in HbA1C was linked to a worrisome 28% rise in the death rate.

Biologic theory and observational studies gave rise to the very reasonable assumption that lower blood sugar levels would translate to better health for diabetics. The next step was to test that belief with clinical trials, which are much more definitive than observational studies. Indeed, two important trials from the 1990s provided additional support for the strategy of tight blood sugar control:

  • The Diabetes Control and Complications Trial studied 1,441 patients with type 1 diabetes. As compared with standard blood sugar control, tight control helped slow the progression of microvascular complications involving kidney, eye, and nerve damage. And a subsequent report covering 17 years of follow-up also linked tight control with a substantial reduction in macrovascular complications, including heart attack, stroke, and death from cardiovascular disease.

  • The United Kingdom Prospective Diabetes Study compared intensive blood sugar control with standard control in 3,867 patients with type 2 diabetes. Intensive treatment significantly decreased the risk of microvascular complications, adding weight to the argument that lower blood sugar levels are better. At the same time, though, intensive control failed to provide significant protection against macrovascular complications, the leading cause of death in diabetics.

Based on all these considerations, the strategy of tight blood sugar control was widely recommended for both type 1 and type 2 diabetes. But that was not the end of the story; instead, scientists launched additional studies.

Recent results

Three randomized trials published in The New England Journal of Medicine between 2008 and 2009 compared tight blood sugar control with standard control in patients with type 2 diabetes, and two studies published in The Lancet in 2010 added additional information. Here’s what they found:

  • The Action to Control Cardiovascular Risk in Diabetes (ACCORD) study compared intensive blood sugar control with standard therapy in 10,251 patients who had type 2 diabetes and cardiovascular disease or major cardiac risk factors. The study was halted ahead of schedule after 3.5 years because of an increased death rate in the patients receiving intensive treatment.

  • The Action in Diabetes and Vascular Disease trial included 11,140 patients with diabetes and vascular disease or at least one vascular risk factor, such as hypertension. After five years, tight glucose control provided protection against microvascular complications (primarily kidney disease) but not against macrovascular complications such as heart attack and stroke. Mortality was similar in patients receiving intensive and standard therapy.

  • The Veterans Affairs Diabetes Trial randomly assigned 1,791 military veterans with type 2 diabetes to either tight or standard blood sugar control. After 5.6 years, the two groups displayed similar rates of microvascular and macrovascular complications and mortality.

  • The United Kingdom’s General Practice Research Database collected comprehensive information on about 47,970 patients with type 2 diabetes. Scientists used these data to evaluate the relationship between blood sugar control and survival in diabetics. As compared with patients who enjoyed moderate blood sugar control (corresponding to median HbA1C levels of about 7.5%), those with both better control (median HbA1C about 6.4%) and worse control (median HbA1C as high as about 10.5%) experienced more cardiac problems and higher death rates.

  • In a 2010 follow-up study, the ACCORD study reported in 2010 that intensive therapy provided very little protection against the microvascular complications of Type 2 diabetes — and these small gains were overshadowed by the cardiovascular risks of tight control.

Dissecting disappointment

Patients with diabetes and the doctors who care for them may be surprised and disappointed that tight blood sugar control has failed to live up to its promise. But they should not conclude that control is unimportant. In fact, a closer look at the data can lead to new and better goals for managing diabetes. Here are some considerations:

  • The evidence at hand still supports tight control for patients with type 1 diabetes; in this population, lowering blood sugar to near-normal levels reduces the risk of both microvascular and macrovascular complications.

  • Tight control is associated with an increased risk of hypoglycemia (abnormally low blood sugar), which can be very dangerous. Tight control is also difficult to achieve, often requiring multiple medications that may have adverse effects of their own, including weight gain. Even a moderate relaxation of blood sugar goals can make life easier for type 2 diabetics while also reducing the cost and complexity of their medical care.

  • Not all patients with type 2 diabetes respond to tight blood sugar control the same way. When researchers analyzed subgroups of patients, they found that those with newly diagnosed diabetes enjoy cardiovascular benefit from tight control, while those with longstanding diabetes and established heart disease do not. It may be that tight control can protect healthy blood vessels from damaging glycosylation, but once damage has occurred, it’s too late for tight control to help.

The sweet spot

Research has modified some long-held assumptions about the treatment of diabetes, and new studies are likely to further refine our standards and goals. Still, some principles seem clear:

1. Diet, exercise, and weight control should be the cornerstone of management for all diabetics. In fact, a healthful lifestyle can prevent many, if not most, cases of type 2 diabetes, and it can lower blood sugar levels and improve the outcome for all patients with the disease.

2. Good blood sugar control is important for all diabetics. Tight control reduces the risk of microvascular complications (kidney disease, nerve damage, and eye disease) in type 1 diabetes. It also helps protect type 1 patients from macrovascular complications (heart attack, stroke, and cardiovascular death); it may have similar benefits for patients with newly diagnosed type 2 diabetes and healthy blood vessels, but is unlikely to help patients with longstanding type 2 diabetes and cardiovascular disease.

Patients who can achieve near-normal blood sugar levels with lifestyle therapy and simple drug programs should do so. Current ADA guidelines call for achieving HbA1C levels of less than 7.0%; this corresponds to an average blood sugar level below 154 milligrams per deciliter (mg/dL). The ADA also recommends striving for fasting blood sugar levels below 131 mg/dL and peak post-meal levels below 180 mg/dL.

3. Patients who take insulin and others who aim for tight blood sugar control should monitor their own blood sugar levels. They should also learn to recognize symptoms of hypoglycemia, including anxiety, racing heart, sweating, tremors, and confusion, and they should know how to raise excessively low sugar levels and how to get help in emergencies.

While the ADA guidelines remain important, many experts believe that one size does not fit all, that blood sugar goals should be adjusted according to the needs of individual patients. In general, an HbA1C target of 7.0% to 7.5%, which corresponds to an average blood sugar level of about 150 to 170 mg/dL, seems reasonable for many patients with type 2 diabetes. Medical therapy should be intensified when HbA1C levels exceed 8%, which corresponds to an average blood sugar level of about 180 mg/dL.

4. Because diabetes is a major cause of cardiovascular disease and premature death, patients should carefully control other risk factors. Current guidelines set targets for diabetics below targets for otherwise healthy individuals; these include blood pressure readings below 130/80 millimeters of mercury (mm Hg) and LDL cholesterol levels below 100 mg/dL. Interestingly, however, reports from the ACCORD investigators suggest that even lower targets for blood pressure do not provide additional benefits for patients with type 2 diabetes.

5. Because special medications can slow the progression of diabetic kidney disease, patients should have regular urine tests for microalbuminuria; blood tests of kidney function may also help. Regular screening for eye disease (diabetic retinopathy) will also lead to helpful preventive treatment. Foot care is important, too.

Diabetes is a chronic condition, and it is a serious illness. Lifelong attention to lifestyle, medication, and monitoring is the key to a good outcome. It’s a challenge for patients, their families, and their doctors — but new emphasis on flexibility and moderation promises to make life easier and better. How sweet it is.

As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

Diabetes by the Numbers


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When you have type 2 diabetes, you’ve got to know your numbers. It’s not just about blood sugar. To successfully manage diabetes, there are several measurements that you should take, or have taken, on a regular basis. Keeping track of the following numbers can help you live well with type 2 diabetes and lower your risk of complications.

Blood sugar levels. This is probably the type 2 diabetes measure you’re most familiar with. Testing your blood sugar regularly allows you to see how certain foods, exercise, and other activities affect your blood sugar levels on a day-to-day basis. Many people with type 2 diabetes need to test once or twice a day to make sure blood sugar levels are in target range. If your blood sugar is very well controlled, you may only need to check a few times a week, according to the National Institutes of Health.

The American Diabetes Association recommends aiming for a blood sugar level between 70 to 130 mg/dl before meals and less than 180 mg/dl one to two hours after a meal. To keep your blood sugar within this range, follow a healthy, well-rounded diet and eat meals and snacks on a consistent schedule. If your blood sugar is not well controlled, talk to your doctor about adjusting your diabetes management plan.

A1C level. This is a blood test, typically given at doctor’s appointments, that measures your average blood sugar levels over a longer period. “It gives you a picture of what’s been going on over the past two to three months,” says Dawn Sherr, RD, a certified diabetes educator and spokesperson for the American Association of Diabetes Educators. Essentially, your A1C result shows how well your diabetes treatment plan is working.

Depending on your results, you may need to have the test from two to four times a year. For most people, an A1C level of 7 percent or less is ideal. If your A1C level is higher, you and your doctor may discuss making changes to your diabetes treatment plan. Healthy lifestyle practices, like consistent blood sugar control and regular physical activity, can help keep your A1C levels low.

Blood pressure. Monitoring your blood pressure is another important way to maintain your health. “People with diabetes are more likely to develop heart disease, and blood pressure is a big factor in that,” Sherr says.

Your blood pressure should be checked several times a year — ideally, every time you see the doctor who is treating your diabetes, Sherr says. Most people with diabetes should aim for a blood pressure of less than 140/80. To prevent high blood pressure, cut back on salt in your diet, exercise regularly, and quit smoking. Some people with type 2 diabetes may need to take medications to lower their blood pressure.

Cholesterol. This is a substance in your body with two components. Low-density lipoprotein (LDL) is known as bad cholesterol; it can build up in your arteries and contribute to heart disease. High-density lipoprotein (HDL) is called the good cholesterol and has a protective effect on your arteries. Your doctor will perform a blood test once a year to check your cholesterol levels, though you may have it checked more often if your numbers are high, Sherr says.

A test result of less than 100 mg/dl of LDL cholesterol is ideal, while HDL cholesterol should be above 40 mg/dl for men and 50 mg/dl for women. Triglycerides, a type of blood fat that can increase your risk of heart disease, should be less than 150 mg/dl for both men and women. If your cholesterol levels are outside these ranges, you can improve them by losing excess weight, exercising, and eating a healthy diet that’s rich in fresh produce and low in fat.

BMI. Short for body mass index, this is a measure that uses your height and weight to estimate how much body fat you have. Since managing weight plays a role in controlling type 2 diabetes, a healthy BMI is important.

Your doctor will probably review your BMI annually, but you can also calculate it yourself by dividing your weight in pounds by your height in inches squared, and then multiplying that number by 703. Online calculators are also available to do the math for you. A healthy BMI ranges from 18.5 to 24.9 — anything over that is considered overweight, and a BMI over 30 is considered obese.

However, the measurement may not be accurate for some people, such as those with a large amount of muscle. “The BMI score can sometimes be deceiving and not the best way to look at the health effects of someone’s weight,” says Fernando Ovalle, MD, an endocrinologist and professor of medicine at University of Alabama at Birmingham College of Medicine. In these cases, other measurements may be used, such as waist-to-hip ratio and abdominal circumference.

Microalbumin. This test measures the amount of protein, or albumin, in your urine, which helps your doctor know how well your kidneys are working. Your doctor should administer this test at least once a year.

The test compares the level of albumin with the level of creatinine, a waste product. Your albumin-to-creatinine ratio should be less than 30, according to the National Institute of Diabetes and Digestive and Kidney Diseases. To keep your microalbumin results within a healthy range, it’s important to keep your kidneys healthy. High blood pressure and high blood sugar can both damage your kidneys, so controlling those factors will go a long way toward preventing kidney problems — and many other health problems — in the future.

Manage Blood Sugar

Most of the food you eat is broken down into sugar (also called glucose) and released into your bloodstream for use as your body’s main source of energy.

Diabetes is a condition in which blood sugar levels are too high. If you have type 1 or type 2 diabetes, it is very important to keep your blood sugar numbers in your target range. You may need to check your blood sugar levels several times each day.

What happens when sugar enters the body?

  • Your pancreas releases insulin when your blood sugar goes up after eating.
  • Insulin acts like a key to let the blood sugar into your body’s cells for use as energy.
  • When blood sugar and insulin are high in the blood, the liver absorbs blood sugar and stores it as glycogen. The liver can turn it back into blood sugar later when it’s needed for energy.

How do I measure my blood sugar levels?

  • If you have type 1 or type 2 diabetes, there are two ways to measure blood sugar:
    • Blood sugar checks that you do yourself. These numbers tell you what your blood sugar level is at the time you test. Blood sugar monitoring is very important for people with diabetes.
    • The A1C test is done in a lab or at your doctor’s office. The A1C test is a measure of the average blood sugar level over the past 3 months. It also helps your health care team decide the type and amount of diabetes medicine you may need.

Managing your diabetes can help keep you from having other serious health problems, such as heart disease, stroke, kidney disease, nerve damage, poor oral health, and vision loss.

What are blood sugar level targets?

A blood sugar target is the individual blood sugar range you try to reach as much as possible. Your health care team may also use the term goal. People who have diabetes have blood sugar targets for different times of the day. Your health care team will recommend a blood sugar target for you. These are typical targets:

  • Before your meal: 80 to 130 mg/dl.
  • Two hours after the start of the meal: Less than 180 mg/dl.

Times to check your blood sugar include the following:

  • When you first wake up (fasting).
  • Before a meal level.
  • Two hours after a meal.
  • At bedtime.

The number of times you check your blood sugar will depend on the type of diabetes you have and if you take diabetes medicine. People who take insulin may need to check more often than people who don’t.

What causes blood sugar to be high or low?

Checking your blood sugar levels regularly helps track what makes your numbers go up and down. For example, being sick, stress, or eating certain foods may cause your numbers to go up. Or when you take your medicine, get more active, or eat less than usual, your numbers may go down.

  • High blood sugar, also known as hyperglycemia, means your blood sugar level is higher than your target level. If this continues over time, it can lead to long-term, serious health problems. Some symptoms of high blood sugar include the following:
    • Feeling very tired.
    • Feeing thirsty.
    • Having blurry vision.
    • Needing to urinate (pee) more often.

If you are sick and your blood sugar stays over 240 mg/dl after 2 checks, call your doctor. If you have type 1 diabetes, be sure to check your urine for ketones. If you have the flu, review flu and sick days for special instructions.

The Big Picture: Checking your Blood Glucose

The Big Picture: Checking Your Blood Glucose

Blood glucose (blood sugar) monitoring is the primary tool you have to find out if your blood glucose levels are within your target range. This tells you your blood glucose level at any one time.
It’s important for blood glucose levels to stay in a healthy range. If glucose levels get too low, we can lose the ability to think and function normally. If they get too high and stay high, it can cause damage or complications to the body over the course of many years.
The logging of your results is vital. When you bring your log to your healthcare provider, you’ll have a good picture of your body’s response to your diabetes care plan. To help keep track of your levels, we have a printable blood glucose log. We also have a blood glucose log available for purchase that is smaller so you can carry it with you.

Who should check?

Talk to your doctor about whether you should be checking your blood glucose. People who may benefit from checking blood glucose regularly include those:

  • taking insulin.
  • who are pregnant.
  • having a hard time controlling blood glucose levels.
  • having low blood glucose levels.
  • having low blood glucose levels without the usual warning signs.
  • have ketones from high blood glucose levels.

How do I check?

People with diabetes check their blood glucose levels by poking their fingertips and using a blood glucose meter or a continuous glucose monitor (CGMs) to measure the blood glucose level at that moment. Read on to find out how to use a blood glucose meter. To find out more about CGMs, start by talking to your doctor.

How to use a blood glucose meter:

  • After washing your hands, insert a test strip into your meter.
  • Use your lancing device on the side of your fingertip to get a drop of blood.
  • Touch and hold the edge of the test strip to the drop of blood and wait for the result.
  • Your blood glucose level will appear on the meter’s display.

Note: All meters are slightly different, so always refer to your user’s manual for specific instructions.
Other tips for checking:

  • With some meters, you can also use your forearm, thigh, or fleshy part of your hand.
  • There are spring-loaded lancing devices that make sticking yourself less painful.
  • If you use your fingertip, stick the side of your fingertip by your fingernail to avoid having sore spots on the frequently used part of your finger.

What are the target ranges?

Blood glucose targets are individualized based on:

  • duration of diabetes
  • age/life expectancy
  • conditions a person may have
  • cardiovascular disease or diabetes complications
  • hypoglycemia unawareness
  • individual patient considerations

The American Diabetes Association suggests the following targets for most nonpregnant adults with diabetes. A1C targets differ based on age and health. Also, more or less stringent glycemic goals may be appropriate for each individual.

  • A1C: Less than 7%
    A1C may also be reported as eAG: Less than 154 mg/dL
  • Before a meal (preprandial plasma glucose): 80–130 mg/dL
  • 1-2 hours after beginning of the meal (postprandial plasma glucose)*: Less than 180 mg/dL

What do my results mean?

When you finish the blood glucose check, write down your results and note what factors may have affected them, such as food, activity, and stress. Take a close look at your blood glucose record to see if your level is too high or too low several days in a row at about the same time. If the same thing keeps happening, it might be time to change your diabetes care plan. Work with your doctor or diabetes educator to learn what your results mean for you. It can take time to make adjustments and get things just right. And do ask your doctor if you should report results out of a certain range right away by phone.
Keep in mind that blood glucose results often trigger strong feelings. Blood glucose numbers can leave you upset, confused, frustrated, angry, or down. It’s easy to use the numbers to judge yourself. Remind yourself that tracking your blood glucose level is simply a way to know how well your diabetes care plan is working, and whether that plan may need to change.

What about urine checks for glucose?

Checking urine for ketones is important when your diabetes is out of control or when you are sick. Talk to your doctor to find out if or when you should check for ketones.

For more information

  • Managing Your Diabetes Glucose four-book set, available from ShopDiabetes.org
  • Enroll in the free Living With Type 2 Diabetes program to get information and support.

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