Why does blood get thick?

Everything you need to know about thin blood

Share on PinterestA CBC test can diagnose thin blood.

Platelets are made in the spleen. Once formed, platelets have a short lifespan of between 7 and 10 days.

Thin blood is due to a low number of platelets. A range of factors may cause a low platelet count, including the following:

Decreased platelet production

Viral infections, such as HIV, hepatitis C, mumps, rubella, or the Epstein-Barr virus may cause platelet numbers to fall.

Bone marrow disorders, such as leukemia and lymphoma, can also affect how many platelets are produced.


Some people take blood-thinning medications to reduce their risk of heart attack and stroke. Two main types of medication thin the blood:

  • Anticoagulants: These include heparin and warfarin, and they work to lengthen the time it takes to form a clot.
  • Antiplatelet drugs: Aspirin is one example and can thin the blood and prevent platelets from forming a clot.

Disorders of the spleen

The spleen produces platelets, so problems with the spleen can cause thin blood. Conditions that affect the spleen include:

  • Splenomegaly, or enlarged spleen.
  • Hypersplenism, which may cause platelets to get trapped in the spleen.

Increased breakdown of platelets

Certain autoimmune conditions, such as rheumatoid arthritis and systemic lupus erythematosus (SLE), can increase the number of platelets that are destroyed. If new platelets are not made fast enough, a person may have thin blood.

Chronic liver disease (CLD)

CLD lowers thrombopoietin levels, which is the hormone responsible for stimulating platelet production. Low thrombopoietin levels reduce the rate at which platelets are produced.

Other facts

There are also some physiological variables that affect platelet count:

  • Aging: Platelet numbers may become lower as a person ages.
  • Genetics: Some people have low platelet counts due to genetic factors.
  • Pregnancy: Low platelet counts affect about 5–7 percent of pregnant women, causing thin blood.

How Thick Is Your Blood?

If you’re at all concerned about heart health, you probably have a good understanding of cholesterol and blood pressure, and likely know your numbers. But there may be another critical blood-related issue to consider — blood viscosity, or blood thickness. According to a health report from Harvard University, people with thicker, more viscous blood may be at a greater risk for a heart attack or for developing heart disease.

That was the case for Sarah Klena, a schoolteacher in Orange County, Fla. Despite living a healthy, active lifestyle, she had a heart attack at age 31. Her doctors suspected blood thickness shouldered part of the blame. “The doctors aren’t really sure what caused it, although they did say I have the stickier type of blood,” she says. “I was a runner and ate pretty well before the heart attack, so since then I’ve just tried to concentrate on anything that improves my health, like acupuncture, massage, yoga, meditation, and, of course, running.”

Blood Thickness: What You Need to Know

If you didn’t know the role blood viscosity plays in heart health, you’re not alone. Most people have no idea how thick their blood is, nor do they know how to make it thinner. But it’s something that should be on most people’s radar for heart health, says Mary Ann Bauman, MD, a national physician spokeswoman for the American Heart Association’s Go Red for Women movement.

“For overall heart health, having a normal viscosity would be ideal,” explains Dr. Bauman. “Viscosity is an indication of the ‘thickness’ of the blood, or its resistance to flowing normally. When the blood is thicker, it moves sluggishly; there is an increased risk for red cells to adhere to one another and form clots, and for there not to be enough oxygenation in a given time to areas such as the legs or the brain, and to vital organs. The heart will work harder to pump the needed oxygen to the body.” She says that blood viscosity can increase because of many factors, such as certain medications, too many red blood cells, high lipid levels, and other conditions, including diabetes and cancer.

There are tests to check for thick blood, but they’re rarely used routinely — “it is usually done in patients who have blood cancers,” says Bauman.

However, there are clues that you may be at risk for a blood viscosity issue. If you have other heart health problems like blood clots or high cholesterol, or you’re a regular smoker, then the chances are also good that your blood might be more viscous than it should be, notes Sriram Padmanabhan, MD, a cardiologist at the MedStar Franklin Square Medical Center in Baltimore.

What You Can Do About Viscous Blood

The good news is that strategies to improve blood viscosity are not too different from those for general heart health. “Exercise definitely helps the blood flow better by improving the health of the arteries, reducing blood pressure, and reducing cholesterol, among other benefits,” says Dr. Padmanabhan. “Quitting smoking goes a long way in improving overall health, reducing the clotting ability of blood and reducing the chance of a heart attack. Reducing fat in our diet, losing weight, keeping cholesterol in check, and keeping blood pressure under tight control all help directly and indirectly in reducing the chance of heart attacks, which is essentially related to blood flow.”

When these measures aren’t enough, you may need to rely on medication and other guidelines from your doctor to reduce your risk. “In general, the ability of blood to flow easily and to clot appropriately is determined by genetics,” adds Padmanabhan. “Some patients will need specific treatments and medications to make their blood flow better.” Schedule regular appointments with your doctor to review your risks and protect your heart health.

Professional Opinion: Does moving to a warmer climate make your blood thin so you can’t take the cold anymore? | Hilton Head Island Packet

Dr. Robert Vyge of Beaufort Memorial Hospital’s Lady’s Island Internal Medicine. Submitted photo

This week, Dr. Robert Vyge, a board-certified internist at Beaufort Memorial Hospital Lady’s Island Internal Medicine, talks about the notion of feeling colder because you’ve developed “thin blood.”

Perfect timing for the winter weather watch that the National Weather Service issued for Beaufort County on Jan. 28 and 29.

Question. Living in the South, we often hear people refer to having “thin blood,” saying they get cold easily. Does blood actually get “thinner” when someone moves — and acclimates themselves — to a warmer climate and does that make them more sensitive to chilly weather than when they lived up North? Does taking a “blood thinner” make a person feel colder?

Answer. No, the concept of developing “thinner blood ” by moving from a colder Northern climate to a warmer Southern climate is only a myth. People may often feel colder at times after moving to the South from the North, but this is not the result of their blood getting thinner. I suspect it has to do with a person’s tolerance to the cold weather changing, or perhaps to a loss of some “insulating” fat that may disappear after living in a warmer climate.

Local News at Your Fingertips

Get unlimited digital access for just $3.99 a month to #ReadLocal anytime, on any device.


The term “blood thinners” has to do with medicines that help prevent blood from clotting. These include aspirin, which works as an anti-platelet agent; warfarin, which works as an anticoagulant; as well as some newer anticoagulants (dabigatran, rivaroxaban and apixaban). Taking a blood thinner should not normally make a person feel colder, and if it did, one should contact their doctor, as this could indicate anemia, potentially from bleeding.

One more concept of blood “thickness” may have to do with an area’s altitude. Living at a high altitude will promote the body to make more red blood cells (to help carry oxygen) and hence “thicken” the blood, while moving to a lower altitude, such as coastal Carolina, could then “thin” the blood. But again, the perception of feeling cold doesn’t have to do with the thinness of the blood.

Follow Laura Oberle at twitter.com/IPBG_Laura.


  • Stroller Strides lets moms get workouts in — with kids in tow
  • Beauty must-have?: Eyelash extensions all the rage in Beaufort County
  • Bluffton woman writes ‘Did I Die?,’ a guide for Alzheimer’s caregivers

Blood Can Be Too Thin or Too Thick

Blood that is too thick can lead to blood clots, and blood that is too thin can lead to easy bruising or bleeding. Problems with blood thickness can occur from birth, or develop later in life. Blood thickness may be affected by foods, drugs, and various medical conditions.

Thick blood may lead to blood clots in the legs, causing a painful, swollen condition called deep venous thrombosis. Sometimes a piece of clot breaks off to lung causing chest pain and shortness of breath- a life threatening condition called pulmonary embolism. Sometimes thick blood causes clots in arteries rather than veins. A blood clot forming in the neck arteries may travel to brain and cause a stroke. A blood clot forming in the arteries of the heart can result in a heart attack. Blood clots cause problems in the affected organ by cutting off oxygen flow.

Thick blood is caused by heavy proteins, or by too much blood in the circulation. Too many red cells, white cells, and platelets will result in blood thickening. Another cause is an imbalance in the blood clotting system. Specific diseases include lupus, inhibitors, deficiency in protein C or S or antithrombin, or mutations in Factor 5 or prothrombin. Cancer can also cause blood thickening.

Not all blood clots are caused by thick blood. Blood clots leading to heart attacks and strokes can be formed when thin blood comes into contact with plaque, which triggers a blood clot. Some blood clots result from sluggish blood flow or poor circulation. People on a long plane or car ride are prone to blood clots if they don’t stretch enough, because of sluggish blood flow in the legs. Obese people are prone to blood clots because their blood flows more sluggishly. An irregular heartbeat called atrial fibrillation causes blood clots, because of sluggish blood flow through the heart.

Blood clots are treated with blood thinners. Some blood thinners like aspirin and plavix make blood platelets less sticky. Others such as heparin or coumadin work by slowing the blood clotting system. Patients are treated with blood thinners for at least 6 months, and sometimes longer depending on the risk of another clot.

Chronic bleeding problems and excessive bruising may be caused by overly-thin blood. Thin blood with bleeding is less common than thick blood with blood clots. Hemophilia and von Willebrand’s disease are two medical conditions that cause thin blood. Hemophiliacs are missing a blood clotting substance, which causes them to bleed into joints. When they start to bleed they are treated with blood thickeners. People with von Willebrand’s disease have easy bruising and bleeding, because their blood platelets lack a sticky coating. Women with von Willebrand’s disease may have heavy periods. A thin-blooded bleeder who needs surgery is given blood thickeners before surgery to prevent bleeding complications.

Is blood like your waistline – the thinner, the better?

Of course, if you’re physically active at work, exercise a lot, or live in a hot climate, you need more fluids. But don’t overdo it. As Dr. Valtin points out in his review, too much water can also be a bad thing.

When it comes to slaking your thirst, you can’t beat water. It has 100% of what you need — plain old H2O — for far less than a penny a glass. But if water just isn’t the beverage for you, there are other ways to get as much as you need:

  • Eat plenty of fruits and vegetables. They’re full of water, and have loads of the minerals, vitamins, and fiber you need.
  • Drink a variety of low-calorie beverages to quench your thirst. Sparkling water, skim or low-fat milk, coffee, tea, and low-calorie soda are good choices. (The calories from whole milk, regular soda, juice, and other sugary beverages can really add up.)

Sensible approach to “thinner” blood

There’s something appealing about the idea that thin, fluid blood is better for you than thick, gooey blood. There are just a few things that stand in its way. First, we don’t really know if it’s true. Second, we don’t have a dipstick for checking blood viscosity. Dr. Kensey hopes that clinicians will buy a device he invented called the Rheolog that can measure blood viscosity in the doctor’s office. Whether this adds anything beyond traditional tests like cholesterol and blood pressure measurements remains to be seen.

In the meantime, it makes sense to exercise, eat a healthy diet, avoid cigarette smoke, and reduce stress. These steps do much more for you than merely thin your blood. If your cholesterol is high, taking a statin makes sense for reasons beyond reducing blood viscosity. Talk with your doctor about whether aspirin is right for you.

What about drinking more water? It’s always a good idea to keep yourself well hydrated. Chronic mild dehydration has been linked with mitral valve prolapse and non-cardiovascular problems such as bladder cancer. It’s a common reason for daytime sleepiness and constipation. Among people over age 65, dehydration is one of the most frequent causes of hospitalization.

Blood thinner misnomer

One of the most commonly used heart drugs is warfarin (Coumadin), a so-called blood thinner. Warfarin doesn’t really alter the thickness (viscosity) of your blood. Instead, it makes it harder for blood to form clots. Warfarin does this by blocking the action of vitamin K, a key player in the body’s clotting cascade.

You have to find the amount of water that’s right for you. The “rule” that we each need eight 8-ounce glasses of water a day turns out to be as much fiction as fact (see “8×8 under fire”). If you can manage an extra glass or two of water a day, so much the better. But if prostate trouble, an overactive bladder, or other problems make urination a chore, then drinking more to theoretically ward off a heart attack or stroke isn’t a good tradeoff.

Image: © Shawn Hempel/Dreamstime

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.

Anticoagulant Medication for Atrial Fibrillation


Anyone with atrial fibrillation is at a very high risk of stroke. Thus anticoagulant medication, also called a blood thinner, is the most common medication used in managing atrial fibrillation. As an afib patient, you are probably on a blood thinner.

When the blood pools in the atria due to an irregular heartbeat from atrial fibrillation, the risk of blood clot formation increases. Anticoagulants decrease that risk by reducing the potential of blood clot formation. Anticoagulants reduce the risk of ischemic stroke by 68 percent, 1 and are recommended regardless of whether you are on rate control medication or rhythm control medication. 2

The body protects you when you get a cut because the blood contains clotting proteins that cause your blood to clot. Vitamin K regulates the creation of these clotting proteins. Anticoagulants work by disrupting the body’s Vitamin K levels, decreasing the body’s production of clotting proteins and thus the propensity to form clots.

If you need anticoagulants, you will receive warfarin, which is the generic, or Coumadin®, which is the brand name. Coumadin® was originally created as a rat poison (rodenticide), so while you are on it you can expect to hear jokes about taking rat poison.

Those jokes would be more amusing if Coumadin® weren’t such a nasty and difficult drug. For some Coumadin® patients, and perhaps even for you, Coumadin® is a nightmare because you are unable to maintain control and keep your vitamin K levels stable.

Risks from Coumadin®

Vitamin K helps to maintain bone strength so those on Coumadin® are at increased risk of bone fractures, particularly in the elderly. Other risks include headaches, dizziness, and very rarely, skin necrosis.

The major risk from Coumadin®, however, is bleeding. The US Food and Drug Administration (FDA) has issued a black box warning that warfarin (Coumadin®) poses a serious and significant health risk due to the potential for major, or even fatal, bleeding.

Because of this, if you are on Coumadin®, consider wearing Medic Alert jewelry at all times and informing medical and dental personnel that you are on Coumadin®. Also, family and friends should be aware of what to do if you have a Coumadin® emergency.

Life on Coumadin®

While Coumadin® works for some patients, it doesn’t work for all. This medication regimen is sometimes difficult to manage, requiring consistency in dosage and diet along with constant blood monitoring and curtailing of many normal activities. It often has nasty side effects as well. For some of us, Coumadin® is life-changing, and not in a good way.

What makes Coumadin® so difficult? It’s necessary to keep your blood thickness within a very tight range, which is measured through a blood test called Protime. It measures your blood thickness on a scale that is called an International Normalized Ratio (INR). Your INR should stay between 2.0 and 3.0, with 2.5 being ideal. If it’s less than 2.0, your blood is too thick and you have the risk of blood clots and stroke. If it’s above 3.0, your blood is too thin and you have the risk of bleeding to death.

One factor that greatly influences your INR and stability on Coumadin® is diet. What you eat can dramatically change your INR almost immediately. Doctors say to eat exactly the same thing in the same quantities at the same time every day. As a practical matter, that’s very difficult to do.

Green vegetables and some other foods, including olives, olive oil, some nuts, and some legumes, are major sources of vitamin K. Knowing what foods contain vitamin K is important if you are on Coumadin®. Keeping vitamin K stable is a key to maintaining a stable INR.

Thus, if you eat green vegetables, as you should, you must eat the same amount of the same ones every day, whether at home, at work, or traveling. That’s not always easy to do, especially if you travel. Your daily dosage of Coumadin® is based on what you need to keep your INR stable, and once stable, theoretically you can continue to eat the same amount of the same things and remain stable. It doesn’t always work that way.

You should also avoid some herbs, such as ginseng, gingko biloba, ginger, garlic, and St. John’s Wort, which can interfere with Coumadin®.

For patients such as our founder, Mellanie True Hills, living on Coumadin® was challenging and life-changing as it was impossible to keep Coumadin® under control no matter how she managed her diet.

If you’re stable, monthly blood draws are sufficient, but being unstable means weekly blood draws, whether you are at home or on the road. Your dosage is tweaked based on each week’s test results as you ping-pong between the risk of clots and bleeding.

If your blood is too thin it leaks from the blood vessels and leaves huge black, blue, and purple bruises all over arms, legs, torso, and even your face. Just being touched or bumped leaves nasty bruises. Mellanie’s family was embarrassed to take her anywhere looking like that.

Activities are severely restricted, too-no yard work, no kitchen knives, no shaving-to avoid getting scratched or cut. It may mean stopping favorite sports or hobbies.

Mellanie was grounded and couldn’t fly. The risk of traveling alone, even driving just an hour away, was too great. Her family traveled with her, and they knew all the hospitals along their route.

When a research study came out that indicated that one-fourth of warfarin (Coumadin®) patients aren’t stable for genetic reasons, she knew that this nightmare couldn’t continue for the rest of her life. That was a huge motivator in her quest for an afib cure.

For more information about afib cures, see Can Afib Be Cured?

| Bookmark | Email Last Modified 12/23/2008

Low Viscosity: 15 Foods that can thin your blood

The thickness of your blood can depend on a number of factors. Your red blood cell count has the most influence on the viscosity of your blood. Blood fats, such as LDL (“bad”) cholesterol, can affect this viscosity – the more LDL you have passing through your bloodstream, the thicker your blood will be.

Other factors such as chronic inflammation, smoking, diabetes, eating habits and even your genetic makeup can all contribute to the varying thinness or thickness of your blood.

Why thinner blood can be beneficial

Research suggests that thinner blood may improve your overall circulation and lower your risk of vascular issues and accidents such as blood clots and hemorrhages that can negatively affect your heart, brain, intestines, eyes, limbs and other organs.

With thicker, “stickier” blood, the heart has to work harder to move it around your body, and if any blockages or obstructions occur, issues like high blood pressure may arise, and you could even suffer a dangerous heart attack or stroke.

Why thinner blood might not be such a good thing

While having thinner blood may stave off any alarming blood circulation issues, blood that is too thin may lead to complications as well. With a lack of platelets in the blood to increase viscosity, continual bleeding – where your wounds and cuts have trouble forming blood clots to stop the bleeding – may cause some amount of frustration, and may even end up becoming a dangerous problem.

For this reason, people who are aware of their blood being thinner than average might want to avoid ingesting certain foods that act as natural blood thinners.

The bottom line

Depending on various factors, including your genetic makeup and your health, you might have a blood consistency that is thinner or thicker than the average person. Always be cautious of what you eat as there are many foods out there that can naturally thin your blood. The gallery above will help to point out some of these particular foods.

Angela Goh

Photos: Getty Images

Health Check: Can eating too much broccoli cause kidney stones?

Why being a fruitarian can be dangerous to your health

Previous post Horoscope Predictions: From 10 to 16 September

Earlier, More Accurate Prediction of Cardiovascular Event Risk
Pushpa Larsen, ND

Ralph Holsworth, DO, recently shared a story with me about a patient he had in Colorado many years ago. He was an intern in a Denver hospital when he admitted a patient diagnosed as having a blood clot in his leg. Dr Holsworth started him on low-molecular-weight heparin subcutaneous injections concurrently with warfarin sodium. He worked the patient up for congenital thrombophilias, cancer, hypothyroidism, and other conditions, and consulted with hematology-oncology on the case. When the patient’s prothrombin time–international normalized ratio exceeded 2.0, Dr Holsworth was instructed by hematology-oncology to discharge the patient. A few minutes later, Dr Holsworth’s pager buzzed. His patient had just collapsed in the parking lot. He rushed down to the emergency department, where cardiopulmonary resuscitation was in progress and assisted in the code. The patient was pronounced dead after several attempts at resuscitation. A mandatory autopsy revealed that the patient had a major pulmonary embolism, resulting in his sudden death.

It was not until several years later that Dr Holsworth learned of the role of whole blood viscosity (WBV) in the formation of thrombi. Dr Holsworth recalled that his aforementioned patient had been discharged with normal vital signs and laboratory test results that provided no indication of the evolving danger. Dr Holsworth later became one of the world’s leading experts in the use of blood viscosity in a clinical setting and asked: “I wonder if this patient would be alive had I been able to evaluate his likely elevated WBV and treat him with antiviscogenic agents. Only then, after lowering his WBV to a safe range, would I have discharged this patient safely to home to his loved ones. I learned early on that a therapeutic international normalized ratio was not to be trusted.”

What Is Blood Viscosity?

Blood viscosity is a measurement of the thickness and stickiness of a patient’s blood. This important hemodynamic biomarker determines the amount of friction against the blood vessels, the degree to which the heart must work, and the quantity of oxygen delivery to the tissues and organs. It is a direct measure of the “flow ability” of blood and is modifiable with existing naturopathic therapies. Blood viscosity is correlated with all known risk factors for cardiovascular disease, including age, sex, smoking, obesity, inflammation, insulin resistance, high blood pressure, low high-density lipoprotein cholesterol, high low-density lipoprotein cholesterol, and others.1-5 Elevated blood viscosity is a strong independent predictor of cardiovascular events.6 In the Edinburgh Artery Study, elevated blood viscosity was the strongest predictor of stroke risk, after controlling all other major risk factors.7,8

It is important to understand the role of blood viscosity as a clinical marker. To do so, one must know something about how the physics of blood flow works and about what affects blood viscosity.

Factors Affecting Blood Viscosity

Five primary factors determine blood viscosity. These include hematocrit, erythrocyte deformability, plasma viscosity, erythrocyte aggregation, and temperature.1


Hematocrit is the most obvious determinant of WBV. A higher percentage of red blood cells (RBCs) results in thicker blood. Hematocrit accounts for about 50% of the difference between normal blood viscosity and high blood viscosity.

Erythrocyte Deformability

Erythrocyte deformability refers to the ability of RBCs to elongate at high velocity and to bend and fold themselves to pass through the slender passageways of the capillaries. More flexible RBCs result in less viscous blood, and young RBCs are more flexible than older RBCs. Erythrocyte deformability is the second most important determinant of blood viscosity, after hematocrit.

Plasma Viscosity

Plasma viscosity refers to the thickness of the fluid portion of blood (everything except for RBCs, white blood cells, and platelets). Plasma viscosity is highly affected by hydration and by plasma proteins, especially high-molecular-weight proteins such as immunoglobulins and fibrinogen.

Erythrocyte Aggregation

Erythrocyte aggregation reflects the tendency of RBCs to be attracted to each other and to stick together. Red blood cell aggregation is complex, with both plasma proteins and RBC deformability having a role.


As with most fluids, blood flows more easily at higher temperatures. It is estimated that a 1°C increase in body temperature results in a 2% decrease in blood viscosity.9

The Physics of Blood Viscosity

Water and plasma are considered newtonian fluids. This means that their viscosity remains the same whether they are flowing fast or slowly. Whole blood, on the other hand, is a non-newtonian fluid, and its viscosity changes with its velocity. This point becomes important clinically when monitoring blood viscosity.

During diastole, blood is subject to lower pressures, or shear. Shear increases rapidly as the ventricles contract in systole and then decreases again as the ventricles relax. During these periods of low shear, the blood slows, cellular components of blood begin to aggregate, and viscosity increases. Blood at diastole can be anywhere from 5 to 20 times as viscous as the same blood at systole. In the next cardiac cycle, viscosity decreases as shear increases and blood components are dispersed, reaching its lowest viscosity at the height of systole (Figure 1).

Viscous Blood Is Abrasive Blood

Blood flows through the vessels in what is described as laminar flow. That is, the blood forms layers (lamina) that slide easily over each other. Looking at the blood vessel from the side, we would see the fastest flowing blood in the center layers, with slower moving blood in the outer layers near the wall of the vessel. Highly viscous blood does not slide as smoothly as less viscous blood, leading to turbulence that can damage the delicate intima of the blood vessel. Turbulence is also generated at curves and bifurcations in blood vessels, particularly the large vessels nearest the heart, which are subject to great changes in pressure with each heartbeat.

Clinical Implications of Altered Blood Viscosity

We see the consequences of hyperviscous blood primarily in damage to the blood vessels, in overwork of the heart, and in decreased delivery of oxygen to the tissues. Highly viscous blood pounding against the walls of the blood vessels leads to abrasion of the single-cell layer of the intima in the carotid, pulmonary, and coronary arteries. The body responds with a protective adaptation, creating a scab (plaque), which eventually calcifies in an effort to protect the blood vessel. The longer-term result, of course, is increased turbulence (because of the no-longer smooth wall) and an ever-narrowing channel for blood flow. This result requires the heart to work harder, pushing the viscous blood out at even higher pressures, further damaging the intimal layer. At the other extreme of the vascular tree, we see decreased perfusion of the tissues as the stiffened erythrocytes of viscous blood scour the capillary linings. The body responds by thickening the capillary walls, decreasing diffusion of oxygen and nutrients into the tissues. This effect is most pronounced in tissues where healthy capillaries are essential for unimpaired function such as the kidneys, eyes, fingers, and toes.

Blood Viscosity Explains Plaque Localization

The effects of blood viscosity, taken together with an understanding of the dynamics of blood flow in a closed circulatory system, explain why it is that atherosclerotic plaques are found only in specific locations in the body.1,10 If cholesterol or inflammation was the primary culprit, plaques would be evenly distributed throughout the body because cholesterol and inflammation are generalized rather than localized. Instead, plaques are found in the curves and bifurcations of the large arteries, and they are located in the exact places where blood flow investigations show that turbulence is the greatest. We all have these areas of turbulent blood flow because we share a common geometry of our vascular tree. Yet, not everyone develops artherosclerotic plaques. The difference lies in the viscosity of the blood traveling through those arteries. Cholesterol and inflammation are important because they contribute to blood viscosity.

Delivery of Oxygen to the Tissues Is Mediated by Blood Viscosity

The capacity of blood to carry oxygen to the tissues is directly correlated with hematocrit. However, it is also inversely correlated with blood viscosity. The relationship of these 2 parameters is expressed as the oxygen delivery index. Within the limits of normal hematocrit values for men and women, improved oxygen delivery index is associated with lower hematocrit levels. A woman with a normal hematocrit actually has a greater ability to deliver oxygen to cells than a man with a higher, but normal, hematocrit.11 The decreased oxygen-carrying capacity of higher-viscosity blood affects cognitive function, as well as the function of any tissue to which robust oxygen delivery is essential (such as the placenta). Given the universal importance of oxygen delivery to the tissues, the relevance of blood viscosity to health maintenance and promotion is clear.

All of this is borne out by hundreds of studies showing that elevated blood viscosity is associated with a host of conditions. A partial list includes diabetes mellitus, insulin resistance, preeclampsia, intrauterine growth retardation, stroke, transient ischemic attacks, atherosclerosis, myocardial infarction, peripheral artery disease, hypertension, headaches, visual field defects, glaucoma, retinopathy, Hodgkin disease, Raynaud disease, sudden deafness, nephrotic syndrome, Alzheimer disease, and more.12-22

The Sex Difference

It is well known that men of any age are at higher risk for cardiovascular events than premenopausal women.11,23 A woman’s risk increases significantly after menopause, and younger women who have hysterectomies are also at increased risk, even if they retain their ovaries (thus an ability to maintain estrogen levels). Why is this? The primary determinants of blood viscosity are highly affected by a woman’s monthly blood loss. The effect on hematocrit is obvious: the monthly loss of 1 to 3 oz of blood will decrease the volume of RBCs. The effect on RBC deformability may be less obvious. Because of monthly bleeding, a woman makes more new blood cells than a man. Her blood contains about 80% more young blood cells and about 85% fewer old blood cells.11 Older RBCs are also more likely to aggregate than are younger RBCs, affecting the third determinant of blood viscosity described herein. In addition, older RBCs are more fragile than younger cells and are more likely to break apart, releasing hemoglobin, a high-molecular-weight protein, into the plasma. Furthermore, plasma-free hemoglobin binds nitric oxide, reducing the ability of nitric oxide to perform its functions as a vasodilator and as an inhibitor of platelet aggregation. Even our fifth determinant of blood viscosity, temperature, may contribute to the lower blood viscosity of premenopausal women because a woman’s basal body temperature is normally increased by 0.5 to 1°C for the second half of her menstrual cycle.

Treatments for Hyperviscosity

We can use the 5 primary determinants of blood viscosity to guide our treatments for hyperviscosity. The objectives of therapy are to optimize hematocrit (Figure 2), improve RBC deformability, decrease plasma viscosity, reduce RBC aggregation, and normalize body temperature.

An easy way to improve blood viscosity is to decrease hematocrit to optimal ranges through blood donation or therapeutic phlebotomy. Dr Holsworth estimates that a hematocrit of 42% is optimal for men, while 38% is optimal for women. Blood donation translates into real-life results. In the Kuopio Ischemic Heart Disease Risk Factor Study,24 a total of 2862 middle-aged men were followed up for a mean of 9 years. During that time, the rate of acute myocardial infarction among non-blood donors was 12.5%, almost 18 times the 0.7% rate among blood donors (P < .001). Blood donation is a win-win solution, but some blood banks shy away from performing “therapeutic” phlebotomy, and many blood banks will not accept donation from the same individual more often than every 2 to 3 months. Protocols are being developed for monthly therapeutic phlebotomy that can be performed in the physician’s office based on a patient’s weight, hematocrit, and systolic and diastolic blood viscosity values.

Erythrocyte deformability is also improved by regular blood donation. New RBCs being produced in bone marrow will be more flexible than older RBCs. Other approaches to increasing RBC deformability include increasing membrane fluidity with nutrient supplementation (such as omega-3 fatty acids) and normalizing insulin sensitivity and blood glucose control. Blood glucose dysregulation results in fluctuations in osmolality that increase RBC rigidity. Evidence also shows that exercise can improve RBC deformability.25

Plasma viscosity is most easily improved with adequate hydration, which can also decrease hematocrit. Research published in the Aviation, Space, and Environmental Medicine journal demonstrated that dehydration increases systolic blood viscosity by 9.3% and diastolic blood viscosity by 12.5%.26 For patients with high blood viscosity, intravenous hydration with normal saline before phlebotomy is advised. It is also important to address plasma proteins, particularly if a patient’s low shear (diastolic) viscosity is elevated. Nattokinase and perhaps other supplements can reduce fibrin. Immunoglobulins can be decreased by addressing food allergies and autoimmunity.

Red blood cell aggregation is affected by RBC deformability and by plasma viscosity, as already noted. Inflammation increases cytokines that affect the polarity of RBCs, making them stickier and more attracted to each other. Infection also increases the tendency to aggregation. Our naturopathic toolboxes are filled with therapies that target inflammation and can improve these parameters.

Normalizing body temperature is just good naturopathic medicine. Increasing the body temperature with constitutional hydrotherapy, the use of daily contrast showers, and optimization of thyroid function are fundamental naturopathic therapies that may have significant effects on blood viscosity.

Several herbs and other natural substances have been shown to lower blood viscosity in animal and human studies.27-30 These include Trigonella foenum and bamboo shoot. The specific determinants of blood viscosity that these herbs affect are unclear, and as with many botanical treatments, more than 1 mechanism may be at play. There are many of these natural therapeutic possibilities, and they are worthy of an entire article by themselves.

Allopathic Antiviscogenic Therapies

Dr Holsworth’s patient described herein was treated with heparin and warfarin yet still developed a blood clot that killed him. We tend to think of warfarin as a blood thinner, but according to Dr Holsworth, he frequently sees patients receiving warfarin therapy who have elevated blood viscosity. Dr Holsworth likens warfarin to additives in concrete that slow down the time it takes for the concrete to set. They do not actually change the viscosity of the cement. Aspirin also does not decrease blood viscosity.

Statins, on the other hand, decrease blood viscosity, and that may be a reason for their effectiveness. Statins come with their own problems, of course. When weaning patients off statins, it would be prudent to monitor blood viscosity.

Measuring WBV

Until now, blood viscosity has been an overlooked parameter in clinical practice, despite the wealth of research on its importance and relevance to a wide range of conditions. Most viscosity testing has been for plasma viscosity, which has usefulness for a narrow range of specific conditions. Plasma, you will recall, is a newtonian fluid, and its viscosity is independent of shear.

The measurement of WBV, rarely ordered by primary care physicians, has been available only through reference laboratories. Whole blood viscosity is generally measured using a viscometer, an older technology originally developed to measure the viscosity of house paint or motor oil. It yields a single measurement that is roughly equivalent to the viscosity of the blood at systolic pressures, when blood is the most fluid and the least sticky. However, as we have seen, blood viscosity is dynamic. Blood that exhibits normal viscosity at systolic shear rates (high shear) may tell a very different story at diastolic shear rates (low shear).

The newest and most advanced testing uses an automated scanning capillary tube viscometer, which is capable of measuring viscosity over the complete range of physiological values experienced in a cardiac cycle (10 000 shear rates) with a single continuous measurement. It is subsequently simplified into 2 measurements, namely, a high shear (systolic) viscosity and a low shear (diastolic) viscosity. This terminology does not refer to the patient’s systolic and diastolic blood pressures but to shear rates that are typically found during systole and diastole. Those shear rates are well established in the blood viscosity research literature.

Who Should Be Tested?

Dr Holsworth believes that blood viscosity is another vital sign that should be monitored regularly just as one would monitor blood pressure. Certainly, when one looks at the number of conditions associated with elevated blood viscosity, it becomes clear that there are few patients for whom monitoring blood viscosity would be unreasonable. The most obvious patients to test for blood viscosity are those with clear cardiovascular risk factors, including smokers, obese individuals, patients with a history of blood clots, and those with insulin resistance, hypertension, or other elevated markers such as C-reactive protein, glycated hemoglobin, low-density lipoprotein cholesterol, fibrinogen, homocysteine, and others. Also included in this list would be women taking oral contraceptives that decrease the frequency of menses. These contraceptives are a double whammy. Not only do they attenuate the natural advantage of monthly blood loss, but the use of oral estrogens is associated with an increased risk for developing blood clots. To this list, I would add anyone with kidney disease, glaucoma, macular degeneration, changes in cognitive function, or autoimmune diseases. My final 2 personal picks are, first, pregnant women or women with any history of preeclampsia or intrauterine growth retardation and, second, young male athletes.

Why young male athletes? Recently, I consulted with a physician on a blood viscosity profile for a 23-year-old man. His blood viscosity values, both systolic and diastolic, were critically high. This young man was a long-distance runner, who took superb care of his body, generally stayed well hydrated, and had otherwise normal laboratory test values and blood pressure. I became curious about this because one hears periodically of young athletes dropping dead in the middle of a game or after a race. A little digging uncovered what to me was a surprising statistic: a young athlete dies of sudden cardiac arrest every 3 days in the United States.31 Ninety percent of those athletes are male.

Pregnant women would normally be considered at lower risk for blood viscosity issues because in pregnancy the increased blood volume is usually associated with hemodilution and with a mildly decreased hematocrit. However, complications of pregnancy (such as preeclampsia and intrauterine growth retardation) are associated with elevated blood viscosity. Dr Holsworth’s observation has been that blood viscosity starts to increase about 6 weeks before the development of hypertension and other signs of preeclampsia. That is a huge clinical window for intervention.

Why Not Just Treat?

A physician recently said to me, “I already know that my patient is likely to have high blood viscosity because of their risk factors. Why not just treat them? Why bother to test?” I test because I want to know how severe a problem I am dealing with. I test to know whether or not my treatments are working adequately or if we need to treat more aggressively.

Blood viscosity allows for earlier, more accurate prediction of cardiovascular event risk than any other risk factor. The predictive value of blood viscosity is made clear in looking at a study7 of 331 middle-aged men with hypertension. These men were stratified into 3 groups by blood viscosity and were followed up for a mean of 5 years. The men in the highest viscosity group had the most cardiovascular events during the study period. The men in the lowest viscosity group—remember that they also had high blood pressure—had the longest event-free survival. The Edinburgh Artery Study,8 as mentioned at the beginning of this article, found that blood viscosity had the highest predictive value for stroke.

Improving our patients’ blood viscosity holds great promise for reducing the risk for cardiovascular and cerebrovascular events, as well as improving health in any condition where perfusion is important. Would cardiologists do well to monitor their high-risk patients’ blood viscosity? Surely, they would. However, most patients see a cardiologist only after they have already had a heart attack or are experiencing symptoms. For naturopathic physicians and other primary care providers interested in preventing disease and helping our patients to thrive, blood viscosity is an invaluable tool that permits earlier detection of developing disease. This allows for sooner treatment, less damage, and improved outcomes. In this way, we come closer to fulfilling our precept to treat the cause.

Pushpa Larsen, ND graduated from Bastyr University (Kenmore, Washington), with training in naturopathic medicine, naturopathic midwifery, and spirituality, health and medicine. She has worked as a research clinician for the Bastyr University Research Institute and as an affiliate clinical faculty member at Bastyr University, training students in her clinic. She practiced in Seattle, Washington, for 10 years before joining Meridian Valley Lab, Renton, Washington, as a consulting physician almost 3 years ago. She consults with hundreds of physicians every year on the use and interpretation of tests offered by Meridian Valley Lab.

Kensey KR, Cho YI. Physical principles and circulation: hemodynamics. In: The Origin of Atherosclerosis: What Really Initiates the Inflammatory Process. 2nd ed. Summersville, WV: SegMedica; 2007:33-50.

Sloop GD, Garber DW. The effects of low-density lipoprotein and high-density lipoprotein on blood viscosity correlate with their association with risk of atherosclerosis in humans. Clin Sci. 1997;92:473-479.

Solerte SB, Fioravanti M. Hemodynamic alterations in long-term insulin-dependent diabetic patients with overt nephropathy: role of blood hyperviscosity and plasma protein changes. Clin Nephrol. 1987;28:138-143.

Dintenfass L. Elevation of blood viscosity, aggregation of red cells, haematocrit values and fibrinogen levels with cigarette smokers. Med J Aust. 1975;1:617-620.

Fossum E. Hoieggen A, Moan A, et al. Whole blood viscosity, blood pressure and cardiovascular risk factors in healthy blood donors. Blood Press. 1997;6:161-165.

Koenig W, Sund M, Filipiak B, Döring A, Löwel H, Ernst E. Plasma viscosity and the risk of coronary heart disease: results from the MONICA-Augsburg Cohort Study, 1984 to 1992. Arterioscler Thromb Biol. 1998;18:768-772.

Ciuffetti G, Schillaci G, Lombardini R, Pirro M, Vaudo G, Mannarino E. Prognostic impact of low-shear whole blood viscosity in hypertensive men. Eur J Clin Invest. 2005;35:93-98.

Lee AJ, Mowbray PI, Lowe GD, et al. Blood viscosity and elevated carotid intima-media thickness in men and women: the Edinburgh Artery Study. Circulation. 1998;97:1467-1473.

Rand PW, Lacombe E, Hunt HE, Austin WH. Viscosity of normal human blood under normothermic and hypothermic conditions. J Appl Physiol. 1964;19:117-122.

Sloop GD. A unifying theory of atherogenesis. Med Hypotheses. 1996;47:321-325.

Kameneva MV, Watach MJ, Borovetz HS. Gender difference in rheologic properties of blood and risk of cardiovascular diseases. Clin Hemorheol Microcirc. 1999;21:357-363.

Hobbs JB, Oats JN, Palmer AA, et al. Whole blood viscosity in preeclampsia. Am J Obstet Gynecol. 1982;142:288-292.

Zondervan HA, Oosting J, Smorenberg-Schoorl ME, et al. Maternal whole blood viscosity in pregnancy hypertension. Gynecol Obstet Invest. 1988;25:83-88.

Coull BM, Beamer N, de Garmo P, et al. Chronic blood hyperviscosity in subjects with acute stroke, transient ischemic attack, and risk factors for stroke. Stroke. 1991;22:162-168.

Ernst E, Matrai A, Marshall M. Blood rheology in patients with transient ischemic attacks. Stroke. 1988;19:634-636.

Coppola L, Caserta F, De Lucia D, et al. Blood viscosity and aging. Arch Gerontol Geriatr. 200;31:35-42.

Ciuffetti G, Mercuri M, Mannarino E, et al. Peripheral vascular disease: rheologic variables during controlled ischemia. Circulation. 1989;80:348-352.

Klaver JH, Greve EL, Goslinga H, et al. Blood and plasma viscosity measurements in patients with glaucoma. Br J Ophthalmol. 1985;69:765-770.

Dintenfass L. Blood viscosity factors in severe non-diabetic and diabetic retinopathy. Biorheology. 1977;14:151-157.

Akhtar N, Thompson J, Durrant ST, et al. The clinical relevance of plasma viscosity in Hodgkin’s disease. Clin Lab Haematol. 1991;13:1-8.

de la Torre JC. Critical threshold cerebral hypoperfusion causes Alzheimer’s disease? Acta Neuropathol (Berl). 1999;98:1-8.

Fowkes FG, Pell JP, Donnan PT, et al. Sex differences in susceptibility to etiologic factors for peripheral atherosclerosis: importance of plasma fibrinogen and blood viscosity. Arterioscler Thromb. 1994;14:862-868.

Salonen JT, Tuomainen TP, Salonen R, Lakka TA, Nyyssönen K. Donation of blood is associated with reduced myocardial infarction: the Kuopio Ischemic Heart Disease Risk Factor Study. Am J Epidemiol. 1998;148:445-451.

Carroll S, Cooke CB, Butterly RJ. Physical activity, cardiorespiratory fitness, and the primary components of blood viscosity. Med Sci Sports Exerc. 2000;32:353-358.

Pais E, Alexy T, Holsworth RE Jr, Meiselman HJ. Effects of nattokinase, a pro-fibrinolytic enzyme, on red blood cell aggregation and whole blood viscosity. Clin Hemorheol Microcirc. 2006;35(1-2):139-142.

Xue WL, Li XS, Zhang J, Liu YH, Wang ZL, Zhang RJ. Effect of Trigonella foenum extract on blood glucose, blood lipid and hemorheological properties in streptozotocin-induced diabetic rats. Asia Pac J Clin Nutr. 2007;16(suppl 1):422-426.

5 Natural Blood Thinning Foods To Reduce Blood Clots And The Risk Of Stroke

Did you know that there are certain foods that we can eat to improve our blood circulation and prevent many heart diseases? Yes, that’s right! There are many blood thinning foods that are known to reduce the risk of clotting. But, before we talk about the variety of natural blood thinning foods, it is imperative to understand what blood clotting is and how it affects our body?
Blood clotting is a normal yet complex process which is known to prevent bleeding when there is an injury or a cut in our body. However, there are times when blood clots form in some critical parts of our body like heart, lung or brain, which if not treated in time, can cause serious complications. These clots may occur in the arterial or venous blood vessels. It is when this clot breaks and travels through the blood, it disrupts the flow of blood to important organs such as heart, lungs or brain, and can result in stroke.
Here are 5 natural blood thinners to reduce blood clots and the risk of stroke:
1. Ginger
One of the best ways to add ginger to your diet is to begin your morning with tasty ginger tea. Research says that sipping ginger tea is quite beneficial and may cure many health problems. And, when it comes to blood thinning, ginger is known to reduce inflammation and further relaxes the muscles. Who knew that a single cup of ginger tea can do wonders for your health.(Also Read: Why Drinking Ginger Water Every Day Is Extremely Beneficial)
2. Cayenne Peppers
Cayenne peppers are power-packed with properties that help in thinning our blood. And, the credit goes to salicylates, which are found in high amount in cayenne peppers. Adding cayenne peppers to our daily diet, in the form of capsules or in the food, could lower your blood pressure and increase circulation.

3. Salmon
It is said that foods that are high in omega-3 fatty acids such as salmon, tuna and trout are one of the best blood thinning foods. It is mainly because omega-3 fatty acids help lower the cholesterol levels in our body. Moreover, they are known to reduce the chances of clotting in the blood.
(Also Read: 9 Incredible Benefits of Salmon Fish You May Not Have Known​)
4. Red Wine
Many experts and nutritionists believe that drinking a glass of red wine every day may help prevent heart diseases, as red wine is known to have properties that help in thinning the blood and further preventing clogged arteries. And, we know how much you fancy drinking red wine, so don’t just get carried away and stick to only one glass a day!
(Also Read: 5 Types of Wines and the Best Time to Enjoy Them​)
5. Cinnamon
We add cinnamon to enhance the taste and fragrance of our dish or drink, especially when added to tea, it tastes bliss. But, did you know that it is a powerful anti-coagulant? Cinnamon is capable of lowering blood pressure and relieving inflammatory conditions. This may reduce the chances of having a stroke. However, long-term consumption of cinnamon may cause liver damage, therefore, make sure you use this spice sparingly.
(Also Read: 6 Reasons Why You Should Be Drinking Cinnamon Water Daily)
CommentsOther than the natural foods and drinks mentioned above, there are other natural foods like pineapple, ginseng, kelp, olive oil, almonds and more that are known to reduce blood clotting. However, it’s important to note that these foods need be taken in moderation. Always speak to your doctor before trying anything that could have an impact on your health.

About Shubham BhatnagarYou can often find Shubham at a small authentic Chinese or Italian restaurant sampling exotic foods and sipping a glass of wine, but he will wolf down a plate of piping hot samosas with equal gusto. However, his love for homemade food trumps all.

Soft matter and liquids

Red blood cells flowing through a blood vessel

Researchers in the US claim that exposing a person to a magnetic field could reduce their risk of a heart attack by streamlining the flow of blood around their body. While the work currently remains just a proof-of-principle, the researchers believe that their technique could ultimately provide an alternative to drugs in treating a range of heart conditions.

Heart attacks and stokes can strike for a variety of reasons. But research suggests that all such vascular conditions are linked by one common symptom – high blood viscosity. Drugs such as aspirin are frequently prescribed to help lower blood viscosity, but these can have unwanted side effects often related to irritation of the stomach. Now, an alternative to drugs may be at hand following recent work by Rongjia Tao at Temple University and his colleague Ke Huang at the University of Michigan.

In their experiment, Tao and Huang showed that applying a 1.3 T magnetic pulse to a small sample of blood can significantly reduce it’s viscosity. About 8 ml of blood with a viscosity of 7 centipoises (cp) – above healthy limits – was contained at body temperature (37 °C) in a test tube. The tube formed part of a device called a capillary viscometer used to measure viscosities. The sample was then exposed to a magnetic field applied parallel to the direction of flow of blood via a coil around the edge of the test tube. After one minute of exposure to the field, the blood’s viscosity had been reduced by 33% to 4.75 cp. With no further exposure to the field, the viscosity had only risen slightly to 5.4 cp after 200 min, which is still within healthy limits.

In a paper accepted for publication in Physical Review E, the researchers describe how the effect is probably caused by the response of red blood cells. These iron-rich cells are the most common type of blood cell and they play the leading role in transporting oxygen around the body. In the presence of a strong magnetic field, the red blood cells form chains that align themselves with the field lines where convoys of red blood cells line up behind a leading cell. This process could enable the cells to pass through the blood in a more streamlined fashion, thus reducing the blood’s viscosity.

Towards clinical trials

Tao says that patients can safely be exposed to magnetic fields of up to 3 T. He intends to develop the work further by testing blood flow under a magnetic field in capillary tubes that are similar in size to blood vessels. He also plans to apply for a research grant from the US National Institutes of Health to allow clinical trials to be carried out.

Kalvis Jansons, a mathematician at University College London, believes that the researchers may be onto something “very interesting”. “If the effect really does exist, it would appear to me that it would not be difficult to use it in a clinical setting,” he says. But he also believes that a lot of work would need to be done to show that the process is safe. “Could it lead to blood clots, for example?” he asks.

Giacinto Scoles, a materials scientist at Princeton University who develops medical applications, believes there is a “tremendous thirst” in the medical community for this kind of physics-based innovation. “I believe the work has raised a lot of interesting questions and that a new field of investigation has been opened up,” he says.

But the medical community will still need to be convinced about the need for the new technology and about its safety. Tammy Ustet, a medical doctor who carries out rheumatology research at the University of Chicago, believes that the main focus should remain tackling the causes of vascular conditions. “Treating symptoms is extremely important, but treating the root cause is the best way to relieve symptoms,” she says.


What causes polycythaemia?

Polycythaemia can be divided into several different types, depending on the underlying cause. In some cases, an underlying cause can’t be identified.

Apparent polycythaemia

“Apparent polycythaemia” is where your red cell count is normal, but you have a reduced amount of a fluid called plasma in your blood, making it thicker.

Apparent polycythaemia is often caused by being overweight, smoking, drinking too much alcohol or taking certain medicines – including diuretics (tablets for high blood pressure that make you pee more).

Apparent polycythaemia may improve if the underlying cause is identified and managed. Stopping smoking or reducing your alcohol intake, for example, may help.

Relative polycythaemia

This is similar to apparent polycythaemia. It can happen as a result of dehydration.

Absolute polycythaemia

“Absolute polycythaemia” is where your body produces too many red blood cells. There are 2 main types:

  • primary polycythaemia – there’s a problem in the cells produced by the bone marrow that become red blood cells; the most common type is known as polycythaemia vera (PV)
  • secondary polycythaemia – too many red blood cells are produced as the result of an underlying condition

Polycythaemia vera (PV)

PV is rare. It’s usually caused by a change in the JAK2 gene, which causes the bone marrow cells to produce too many red blood cells.

The affected bone marrow cells can also develop into other cells found in the blood, which means that people with PV may also have abnormally high numbers of both platelets and white bloods cells.

Although caused by a genetic change, PV isn’t usually inherited. Most cases develop later in life. The average age at diagnosis is 60.

Secondary polycythaemia

Secondary polycythaemia is where an underlying condition causes more erythropoietin to be produced. This is a hormone produced by the kidneys that stimulates the bone marrow cells to produce red blood cells.

Health conditions that can cause secondary polycythaemia include:

  • chronic obstructive pulmonary disease (COPD) and sleep apnoea – these can cause an increase in erythropoietin, due to not enough oxygen reaching the body’s tissues
  • a problem with the kidneys – such as a kidney tumour or narrowing of the arteries supplying blood to the kidneys

5 Things You Need to Know About Thick Blood Disease

There’s a saying that “blood is thicker than water,” but blood that is too thick can be a serious medical issue. Although uncommon, there are some disorders that cause thick blood — including those that lead to an abnormally high number of blood cells and conditions that cause hypercoagulation, or excessive blood clotting 3. These disorders can lead to serious, life-threatening consequences, so early detection and treatment are important.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

Excess Blood Cells

Certain diseases, namely blood cancers, thicken the blood because they lead to abnormally high levels of blood cells. While rare, one of the more common reasons for thick blood is called polycythemia vera (PV), in which the body produces excessive blood cells — mostly too many red blood cells. PV is caused by a genetic mutation and typically develops slowly, over several years.

Waldenstrom macroglobulinemia is a type of non-Hodgkin lymphoma, or blood cancer, that causes overproduction of an antibody — a type of blood protein — called immunoglobulin M. Myeloma is a blood cancer caused by abnormal and uncontrolled growth of plasma cells — a type of white blood cell that produces antibodies 5. These conditions can also cause thick blood, crowding the blood with abnormal antibodies, leaving too few of the infection-fighting antibodies.

Excess Clotting

When you suffer a wound or cut, your body forms a blood clot to stop the bleeding — a process called coagulation. The clot is formed from blood proteins called fibrins and platelets, or cell fragments. Typically, your body breaks down the clot. However, sometimes blood clots form too easily or do not dissolve properly. This excessive clotting — hypercoagulation — also causes thick blood 3. This can be dangerous since clots can form inside your blood vessels and block blood flow to tissues or organs. Hypercoagulation may be caused by genetic disorders or it may be associated with acquired conditions such as certain autoimmune diseases and cancers, pregnancy or certain medications.

Health Effects

Thick blood flows more slowly than normal blood, which deprives body organs and tissues of the amount of oxygen required for necessary function. Side effects include headaches, dizziness, fatigue, itchiness and vision problems. High levels of abnormal white blood cells can cause anemia, tiredness, weight loss, bone pain and frequent infections. Most seriously, people with thick blood — whether from excessive blood cells or hypercoagulation — are at high risk for clots that block or limit blood flow to vital organs. The possible consequences include a stroke, heart attack or serious damage to other organs such as the kidneys or lungs.

Medical Treatment

Many people are not diagnosed with these conditions until later in life. However, sometimes these disorders are uncovered by routine blood tests, through personal or family medical histories or when a doctor is investigating the cause of early symptoms such as tiredness or anemia. Depending on the severity and underlying cause of thick blood, there may be ways to correct the disorder or reduce the risk of related complications. Phlebotomy — the removal of some blood — or medications are treatments aimed at reducing blood cell numbers. Blood thinning medications such as warfarin (Coumadin) can reduce clotting. Consultation with a physician specializing in blood disorders will determine the best course of action for your specific condition.


Most importantly, immediate medical care is needed if a blood clot, stroke or heart attack is suspected. A blood clot in the leg can cause redness, pain, warmth and swelling in the lower leg. A heart attack or a blood clot in the lungs or heart can cause:

  • shortness of breath
  • chest pain
  • chest heaviness or pressure
  • discomfort in the neck
  • jaw
  • upper back or arms

Symptoms of a stroke include difficulty speaking or understanding speech, headaches or paralysis that is typically on one side of the body. These symptoms require emergency medical care to determine the cause and receive live-saving treatment as soon as possible.

About the author

Leave a Reply

Your email address will not be published. Required fields are marked *