A high red blood cell count, medically known as erythrocytosis or polycythaemia, is a condition in which the number of red blood cells in the bloodstream exceeds normal levels. While these cells are important for our survival, excess can lead to a range of health issues, from minor discomfort to potentially life-threatening complications such as blood clots, strokes, and heart attacks.

Types of High Red Blood Cell Count

Primary erythrocytosis: It is a rare condition caused by a genetic mutation in the bone marrow, the factory where red blood cells are produced.
Secondary erythrocytosis: This is a more common type of erythrocytosis caused by an underlying medical condition. The condition stimulates the bone marrow to produce too many red blood cells.

Symptoms of High Red Blood Cell Count

Not everyone who has a high blood count experiences symptoms certainly, but the following symptoms must be watched for:

Blood flow problems: The thicker blood can cause headaches, dizziness, fatigue, blurred vision, and confusion.
Skin issues: Itching, especially after a warm bath or shower, and skin redness, particularly on the face, hands, and feet (may be harder to see on darker skin tones).
Circulatory problems: High blood pressure and an increased risk of blood clots can lead to serious complications like strokes and heart attacks.
Other symptoms: Discomfort in the abdomen, bleeding problems (frequent nosebleeds, easy bruising), gout (causing joint pain, stiffness, and swelling), and tingling or burning sensations in the extremities.

Causes of High Red Blood Cell Count

This condition of erythrocytosis can be caused due to the following reasons:

Primary causes:

Polycythemia vera: A rare bone marrow disorder where the body produces too many red blood cells.
Secondary causes (also known as secondary polycythemia):

Environmental factors:

High altitude living: The body produces more red blood cells to compensate for lower oxygen levels.
Smoking: Carbon monoxide from smoking triggers increased red blood cell production.

Medical conditions:

Chronic lung diseases (e.g., COPD, sleep apnea): These reduce oxygen in the blood, stimulating red blood cell production.
Heart diseases: Certain congenital heart defects can increase red blood cell production.
Kidney tumours: Some tumours produce excess erythropoietin, a hormone that stimulates red blood cell production.
Liver diseases: Certain liver conditions can affect red blood cell regulation.

Hormonal causes:

Androgen use: Testosterone and anabolic steroids can boost red blood cell production.
Erythropoietin doping: Misuse of this hormone, sometimes seen in athletes.
Dehydration: It can cause a temporary increase in red blood cell concentration.

Genetic factors:

Certain inherited disorders can lead to increased red blood cell production.

Apparent polycythemia:

This occurs when the plasma volume is reduced, making it appear as if there's an increase in red blood cells, even though the total number hasn't changed.

Risks of High Red Blood Cell Count

High blood count often causes life-threatening complications within the body:

Blood clots: The primary concern is an increased risk of thrombosis (blood clots). Excess red blood cells can make the blood thicker and more viscous, increasing the likelihood of clot formation. These clots can occur in:

Deep veins (deep vein thrombosis)

Lungs (pulmonary embolism)

Brain (stroke)

Heart (heart attack)

Cardiovascular problems: The thickened blood can strain the heart, potentially leading to:

Hypertension (high blood pressure)

Heart failure

Enlarged heart

Spleen enlargement: The spleen may enlarge as it works harder to filter the increased number of blood cells.

Liver problems: In some cases, liver function may be affected, leading to hepatomegaly (enlarged liver).

Gout: Increased cell turnover can lead to elevated uric acid levels, potentially causing gout.

Itching (pruritus): Some patients experience severe itching, especially after warm showers or baths.

Vision problems: Disturbances in vision may occur due to reduced blood flow or small eye clots.

Bleeding problems: Paradoxically, despite increased blood thickness, some patients may experience easy bruising or bleeding due to associated platelet dysfunction.

Hyperviscosity syndrome: In severe cases, extreme blood thickness can lead to neurological symptoms, including confusion, dizziness, and headaches.

Pregnancy complications: In pregnant women, a high red blood cell count can increase the risk of pregnancy loss, growth restriction, and preeclampsia.

Treatment of High Red Blood Cell Count

The treatment for a high red blood cell count (RBC) or high haemoglobin count depends on the underlying cause but can include the following:

Phlebotomy (blood removal): This is the primary treatment for polycythaemia vera, a condition that causes overproduction of red blood cells. Regularly removing small amounts of blood can help lower the RBC count.
Medications: For polycythaemia vera, hydroxyurea (Hydrea) may be prescribed to slow down red blood cell production. Aspirin and antihistamines can also help manage symptoms like headaches and itching.
Lifestyle changes: In some cases, reducing the intake of iron-rich foods, avoiding dehydration, quitting smoking, and regular exercise can help lower a high RBC count.
Treating underlying conditions: For secondary polycythaemia caused by heart, lung, or kidney disorders, treating the underlying condition may help normalise the RBC count.

Prevention of High Red Blood Cell Count

This life-threatening problem can be prevented, and here are some ways to do so:

Quit smoking
Exercise regularly
Stay well hydrated by drinking plenty of water
Avoid iron supplements and iron-rich foods
Limit intake of coffee, soda, and other diuretics
Avoid anabolic steroids and performance-enhancing substances
If you have sleep apnoea, use proper medical devices like a CPAP machine
If you have heart failure, strictly adhere to your treatment plan
Manage underlying conditions like heart, lung or kidney disease that can cause secondary polycythaemia

For primary polycythaemia vera, the main preventive measures are:

Regular phlebotomy (blood removal) to keep red blood cell levels under control
Medications like hydroxyurea to slow red blood cell production
Low-dose aspirin to reduce clotting risk and improve symptoms
Antihistamines to relieve itching

The key is to work closely with the healthcare provider to determine the cause of a high red blood cell count and implement the appropriate prevention and treatment plan. Maintaining a healthy lifestyle and managing underlying conditions are important steps to keep the red blood cell count in the normal range.

Reference links:

https://www.acko.com/health-insurance/high-red-blood-cell-count/
https://my.clevelandclinic.org/health/symptoms/17810-high-red-blood-cell-count
https://pharmeasy.in/blog/what-causes-high-red-blood-cell-count-insights-into-hematological-disorders/
https://www.healthline.com/health/rbc-count