How to Lower Hematocrit – A Guide by CARE

In this article, CARE will delve deep, literally speaking, into your blood and explain the most important things relating to hematocrit. We will explore why hematocrit is important, the normal level of hematocrit that you would wish to see in your blood test, methods – natural and drug-related – for lowering hematocrit, causes of elevated hematocrit counts, and the associated risks.

Are you ready to learn more about your blood? Then, let’s get bloody started.

What Is Hematocrit? — The Percentage of Red Blood Cells

Hematocrit, often abbreviated as Hct, is a critical component of a complete blood count (CBC) test. It represents the percentage of red blood cells (RBCs) in your total blood volume, giving an indication of the blood's oxygen-carrying capacity. But how so?

Red blood cells (RBCs) are the primary players in the blood's oxygen-carrying capacity. Hematocrit, as a measure of the proportion of RBCs in the total blood volume, directly reflects the blood's ability to transport oxygen and can be an indicator for certain diseases as well. [1]

RBCs contain hemoglobin, a protein that binds with oxygen in the lungs and releases it to body tissues. When hematocrit levels are higher, there are theoretically more RBCs available to carry oxygen, but since too many RBCs thicken the blood, this can result in a decreased oxygen-carrying capacity. Therefore, neither too low nor too high hematocrit levels favor your blood’s oxygen-carrying capacity. [1]

So, in essence, hematocrit measures the concentration of red blood cells within the blood, which allows health specialists to draw conclusions about your overall health and determine further diagnosis.

Before we explore the causes and risks of high hematocrit levels, let’s take a look at what hematocrit levels are considered healthy and normal.

What Are Typical Hematocrit Levels?

The normal range for hematocrit levels can vary slightly depending on factors like age, sex, and medical history. However, a general range for typical hematocrit levels in adults is approximately 36% to 48% for women and 41% to 50% for men. [2]

These are the normal reference hematocrit levels published by the American Red Cross, who are specialists in this field, considering they take thousands of blood donations each month.

You may already know that your hematocrit levels are too high, or you just realized after taking a look at the reference levels from the Red Cross. [2]

You probably ask yourself now, what causes too high hematocrit levels? Worry not; we’ve got you covered and will give you a broad overview of potential causes of elevated hematocrit counts.

What Causes Elevated Hematocrit Counts?

Elevated hematocrit levels, if they are caused by too many red blood cells in your blood, medically referred to as polycythemia, can be caused by various factors, both physiological and pathological. The potential causes of elevated hematocrit counts can be completely harmless and easy to eradicate or more serious in nature.

Understanding the underlying causes is crucial for diagnosis and treatment in order to get back to normal hematocrit levels. We will now explore potential causes for high hematocrit levels in detail.

Dehydration – Water Is Life

Dehydration is one of the most common and reversible causes of elevated hematocrit levels.

When your body loses fluids due to insufficient fluid intake or excessive loss through activities like intense exercise or sweating, your blood becomes more concentrated with red blood cells, leading to an increase in hematocrit. [3]

Smoking – Carbon Monoxide, The Enemy Of Oxygen

Smoking is a well-known factor contributing to higher hematocrit levels. The carbon monoxide in cigarette smoke binds to hemoglobin more tightly than oxygen, reducing the oxygen-carrying capacity of red blood cells. [4]

In response, your body may produce more RBCs to compensate, raising hematocrit levels.

Are You A Mountaineer? — Living at High Altitudes

Do you live on a mountain? At higher altitudes, there is reduced oxygen in the atmosphere, which stimulates the body to produce more red blood cells to enhance oxygen transport.

This adaptation to lower oxygen levels can result in elevated hematocrit levels among those who reside or spend significant time at high altitudes. [3]

Chronic Lung Conditions – COPD

Conditions that cause chronic hypoxia, or low oxygen levels in the blood, can lead to secondary polycythemia. Chronic obstructive pulmonary disease (COPD), for example, can reduce oxygen intake, prompting the body to increase red blood cell production. [3]

Many cases of COPD can be traced back to smoking – therefore, smoking should be avoided for the sake of your lungs and your overall health.

Polycythemia Vera – A Blood Disorder

Polycythemia vera is a rare and chronic blood disorder characterized by the overproduction of red blood cells in the bone marrow. This condition is primarily caused by genetic mutations, specifically in the JAK2 gene. [3]

Individuals with polycythemia vera have excessively elevated hematocrit levels, which can lead to various health complications.

Renal (Kidney) Disorders

The kidneys play a crucial role in regulating the production of red blood cells by secreting erythropoietin, a hormone that stimulates RBC production. Certain kidney disorders can result in an overproduction of erythropoietin, leading to elevated hematocrit levels. [5]

Congenital Heart Diseases

Some congenital heart defects can lead to chronic hypoxia, causing the body to produce more red blood cells. Also, children born with cyanotic heart diseases, which affect blood oxygen levels, may develop elevated hematocrit as a result. [3]

Doping or Hormone Therapies

Certain medications and hormone therapies can affect red blood cell production. Anabolic steroids, used for various medical conditions or performance enhancement, can stimulate RBC production and raise hematocrit levels. [6]

TRT – Testosterone Replacement Therapy

Testosterone Replacement Therapy (TRT) is a medical treatment that provides testosterone to individuals with low or deficient testosterone levels.

While TRT can provide many benefits, it can also lead to elevated hematocrit levels in some individuals since testosterone has a direct impact on the bone marrow, where red blood cells (RBCs) are produced. When individuals undergo TRT, especially when receiving high or excessive doses of testosterone, it can stimulate the bone marrow to produce more RBCs. This is because testosterone acts as a growth factor for erythropoiesis, the process of RBC production. [7]

What Are The Risks of High Hematocrit?

We conclude that elevated hematocrit counts can be caused by a variety of factors, including dehydration, smoking, living at high altitudes, and underlying conditions. But what are the risks associated with an increased amount of red blood cells, and what are potential health problems that can arise?

We will now discuss and showcase the potential risks associated with high hematocrit levels.

Increased Blood Viscosity

Elevated hematocrit levels can lead to thicker, more viscous blood. This can hinder blood flow, increasing the risk of cardiovascular diseases such as hypertension and thrombosis. [9]

Reduced Oxygen Delivery

Higher hematocrit levels can result in reduced oxygen delivery to your body’s tissues, leading to symptoms like fatigue, shortness of breath, and poor exercise tolerance. [9]

But should it not be the other way around since red blood cells contain the protein hemoglobin that is responsible for oxygen transport? Well, since too many red blood cells can thicken your blood, it makes them less able to travel through blood vessels and organs, which can result in reduced oxygen deliverability.

Increased Risk of Stroke

Thicker blood can lead to an increased risk of clot formation, which may cause ischemic strokes. An ischemic stroke can be related to thick blood, a condition known as hyperviscosity or hypercoagulability because thickened blood is more prone to forming clots. [9]

When blood is thicker than normal, it can create a higher risk of blood clots, which, if they travel to the brain, can block blood vessels and lead to an ischemic stroke by depriving brain tissue of oxygen and nutrients.

Cardiovascular Strain

High hematocrit levels can place additional strain on the heart, potentially accelerating  heart-related conditions, such as congestive heart failure, if the high hematocrit levels are present over an extended period of time. [9]

Impaired Microcirculation

Microcirculation refers to the smallest blood vessels in the circulatory system, including arterioles, capillaries, and venules, where the exchange of oxygen, nutrients, and waste products occurs at the cellular level.Thickened blood can impact microcirculation, affecting tissue health and potentially leading to organ damage. [9]

High hematocrit levels can lead to increased blood viscosity, making it more challenging for RBCs to navigate the narrow microvessels, potentially impairing the efficient exchange of oxygen and nutrients with surrounding tissues.

Okay, so how, if you don’t already know, can you find out about your hematocrit levels?

Hematocrit Blood Test – The Packed-Volume-Test (PCV)

Your blood is a mixture of cells and plasma. The packed cell volume test (PCV) is a measurement of the proportion of blood that is made up of cells to determine your hematocrit levels.

The hematocrit blood test/packed volume test is a routine laboratory procedure that measures the proportion of red blood cells (RBCs) in the total volume of your blood. This test provides valuable information about blood composition, which can be instrumental in diagnosing various medical conditions and monitoring your overall health.

Hematocrit testing is also a fundamental component of a complete blood count (CBC), a standard blood test that evaluates the cellular composition of blood. Understanding the significance of hematocrit testing is crucial for healthcare professionals and patients alike.

Since CARE is a specialist in detailed blood analysis, we have summarized how your blood sample is tested for hematocrit levels.

1. Blood Sample Collection

One of our CARE healthcare professionals, or your physician, collects a blood sample from you. This is done by inserting a small needle into a vein, usually in your arm.

2. Blood Separation

The collected blood sample is placed in a specialized tube that prevents clotting. The tube is then sent off to a laboratory, where it gets centrifuged, a process that involves spinning the blood at high speeds.

This centrifugation separates the blood into its constituent components: plasma, RBCs, white blood cells, and platelets.

3. Measurement of Hematocrit

After centrifugation, the volume of packed RBCs at the bottom of the tube is measured as a percentage of the total volume of blood. This percentage is your hematocrit value.

Since you have already learned about the causes of too high hematocrit levels, you know that a normal and healthy hematocrit count is essential for your overall health.

The main reason for the potential drastic risks of having a hematocrit count that is too high is closely connected with hemoglobin.

What Is the Relationship Between Hematocrit And Hemoglobin?

Imagine your bloodstream as a bustling highway, with red blood cells (RBCs) being the cars carrying precious cargo – oxygen – to every corner of your body.

Hematocrit – Measuring RBC Efficiency

Hematocrit (Hct) is like a helicopter flying over that bustling highway, telling us how many RBCs are navigating this vital highway and if the traffic is still flowing efficiently. A higher hematocrit level means more RBCs cruising through your bloodstream. [2]

Hemoglobin – The Oxygen Shuttle

Hemoglobin (Hb) is the chauffeur within each RBC since it is responsible for carrying oxygen, and it can carry a whole load of it at once. Imagine an efficient shuttle service for oxygen. [2]

The Dynamic Connection – Hematocrit and Hemoglobin

The fascinating part is how hematocrit and hemoglobin are connected with one another. When hematocrit levels go up, it's like the highway gets busier with more RBCs, and naturally, the hemoglobin concentration also increases – the “roads,” meaning your veins, can become a little crowded, meaning your blood thickens. If the road is packed, this can hinder the RBCs from transporting the oxygen to all the important little vessels and organs of your body.

In this scenario, hematocrit is the helicopter circling above the highway that provides us with information about how many cars (RBCs) are on the road and indicates how efficiently the chauffeurs (hemoglobin) can transport the oxygen to their destination.

So, what are ways to lower your hematocrit?

How to Lower Hematocrit Levels Naturally?

In an attempt to obtain better health, we often seek natural remedies to tackle health-related issues. When it comes to managing elevated hematocrit levels, there are indeed lifestyle changes and natural methods that can help you lower your hematocrit naturally.

But how can you reduce hematocrit levels? Dietary modifications, increased hydration, and regular exercise are some of the methods available to you. Implementing these strategies can help normalize hematocrit levels without the need for medical intervention.

Let's delve into these natural approaches, understanding how they work and how they can lower your hct levels.

Hydration – The Elixir of Life

One of the simplest and most effective ways to lower hematocrit is by staying well-hydrated and managing your fluid intake. When you are adequately hydrated, your blood becomes less concentrated, meaning there are more fluids to dilute the number of red blood cells. This reduces the proportion of RBCs in your blood, effectively lowering hematocrit. [8] [10]

Dietary Changes – Iron in Check

Diet plays a significant role in hematocrit levels, particularly when it comes to iron intake.

Reducing the consumption of iron-rich foods can help lower hematocrit. Avoiding excessive red meat, organ meats, and iron supplements can be a smart move, as these sources of heme iron can stimulate the production of more RBCs. [8]

Regular Physical Activity – Get Moving

Exercise is a fantastic way to promote blood flow and reduce hematocrit levels naturally. Physical activity not only increases the efficiency of oxygen transport but also stimulates the production of vasodilators, which help expand blood vessels. This, in turn, helps reduce the concentration of RBCs. [8]

Phlebotomy – Bloodletting

While not entirely natural, phlebotomy is a medical procedure that mimics the natural process of bloodletting. During phlebotomy, a healthcare professional removes a specific volume of blood from your body. This reduces the number of RBCs in circulation and consequently lowers hematocrit levels.

While it's not something you can do at home, it is a treatment provided by healthcare professionals that does not necessitate medication.

Eating More Grapefruits

Grapefruit is rich in compounds known as flavonoids, which have been associated with potential effects on blood viscosity and clotting. Consuming grapefruit may help promote blood thinning, which could indirectly lead to a reduction in hematocrit levels by making blood less viscous and less prone to clot formation. [11]

What Medications & Supplements Are Effective For High Hematocrit?

In some cases, natural methods alone may not be sufficient to lower elevated hematocrit levels. When this occurs, your healthcare professionals may recommend medications or supplements to manage the condition.

We will now list some of the available medications and provide insights into their effectiveness and potential side effects. Naturally, drug-related therapies need to be prescribed by your doctor.

Hydroxyurea – Slowing RBC Production

Hydroxyurea is a medication that works by inhibiting the production of RBCs in the bone marrow. By slowing down the creation of new RBCs, hydroxyurea effectively reduces the hematocrit and the overall thickness of the blood. [12]

This treatment is often used in cases of chronic myeloproliferative disorders and may require close monitoring by your healthcare provider.

Interferon Alpha – Regulating RBC Production

Interferon alpha is another medication used to control the overproduction of RBCs in conditions like polycythemia vera. It regulates the production of RBCs, white blood cells, and platelets, ultimately reducing hematocrit levels. [13]

Aspirin – Managing Blood Viscosity

Aspirin is used as an adjunct therapy to manage the increased risk of blood clots associated with elevated hematocrit levels. While it doesn't directly lower hematocrit, aspirin helps prevent clot formation by inhibiting platelet aggregation. This is particularly important in individuals with polycythemia vera. [14]

Why Should You Care About Your Hematocrit Levels?

Your hematocrit levels are a reflection of the health and balance of your blood. Even though there are momentary and rather harmless causes of high hematocrit levels, like dehydration, there are also more serious causes that need to be detected early on to prevent long-term health issues. [1] [2]

Catching Disorders or Illnesses Early: When hematocrit levels soar alongside elevated hemoglobin concentrations, it might be an indicator of polycythemia vera, a bone marrow disorder where you have too many RBCs. Health conditions like these or kidney tumors can cause a tandem rise in hemoglobin and hematocrit. [1] [3]

Tracking Blood Disorders: For those with blood disorders, hematocrit and hemoglobin levels are like road signs. They help your healthcare provider navigate the treatment of your condition, whether it's getting better or taking a detour.