High Red Blood Cell Count

A high red blood cell count, also known as erythrocytosis or polycythemia, is a condition where the body produces too many red blood cells. This can lead to an increased risk of blood clots and other complications.

Causes

  • Primary polycythemia: A rare disorder in which the bone marrow overproduces red blood cells due to a genetic mutation.
  • Secondary polycythemia: Caused by external factors such as:
    • High altitude
    • Chronic lung disease
    • Heart disease
    • Kidney tumors or cysts
    • Testosterone replacement therapy
  • Relative polycythemia: Caused by a decrease in plasma volume, which can occur due to:

Symptoms

Symptoms of a high red blood cell count may include:

Diagnosis

Diagnosis is typically made through a combination of:

  • Complete blood count (CBC): To measure the number of red blood cells, white blood cells, and platelets in the blood.
  • Blood smear: To examine the shape and size of red blood cells.
  • Genetic testing: To identify genetic mutations that may be contributing to the condition.
  • Imaging tests: Such as ultrasound or CT scans, to rule out underlying conditions such as kidney tumors or cysts.

Treatment

Treatment for a high red blood cell count depends on the underlying cause and may include:

  • Phlebotomy: Regular removal of blood to reduce the number of red blood cells.
  • Medications: To reduce the production of red blood cells or prevent blood clots.
  • Oxygen therapy: To increase oxygen levels in the blood.
  • Treatment of underlying conditions: Such as chronic lung disease or heart disease.

Complications

If left untreated, a high red blood cell count can lead to complications such as:

Frequently Asked Questions (FAQs)

What is a high red blood cell count?
A condition where the body has too many red blood cells, also known as erythrocytosis.

What are the possible causes of a high red blood cell count?
Dehydration, smoking, living at high altitudes, or underlying medical conditions such as polycythemia vera.

What are the symptoms of a high red blood cell count?
Headaches, dizziness, itchiness, or redness and warmth of the skin, although some individuals may be asymptomatic.

How is a high red blood cell count diagnosed?
Through a complete blood count (CBC) test, which measures the levels of different components of the blood.

What are the risks associated with a high red blood cell count?
Increased risk of blood clots, heart attack, or stroke due to thickened blood.

Can a high red blood cell count be treated?
Possibly, depending on the underlying cause, through phlebotomy, medication, or addressing the underlying condition.

What is phlebotomy in the context of a high red blood cell count?
A procedure where a portion of the blood is removed to reduce the concentration of red blood cells.

Are there any lifestyle changes that can help manage a high red blood cell count?
Possibly, staying hydrated, avoiding smoking, and managing underlying conditions may help.

Can a high red blood cell count be prevented?
Maybe, depending on the cause, by addressing risk factors such as dehydration or smoking.

Is a high red blood cell count always a sign of an underlying condition?
Not necessarily, as it can also be caused by external factors such as altitude or dehydration.

Article last updated on: 18th October 2025.
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