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Erythrocytosis (High Red Blood Cells)


Erythrocytosis is characterized by an abnormally high quantity of red blood cells (erythrocytes) in the blood. Your blood comprises solid components such as red blood cells, white blood cells, and platelets. It also has a liquid component known as plasma. Erythrocytosis is defined as having an abnormally high number of red blood cells (a solid part) compared to plasma (a fluid component).

  • Erythrocytosis is characterized by elevated hematocrit and hemoglobin levels.
  • Hematocrit levels are the number of red blood cells in your body.
  • Hemoglobin levels is a protein found in red blood cells that is necessary.


Erythrocytosis, or polycythemia, is a medical disorder marked by an excessively high quantity of red blood cells in the blood. Several underlying erythrocytosis causes can be classified as primary and secondary variables. Primary erythrocytosis is frequently associated with genetic abnormalities in genes that govern the generation of red blood cells in the bone marrow, such as JAK2. Secondary erythrocytosis, on the other hand, is usually caused by outside sources.

Chronic hypoxia, when the body’s oxygen supply is diminished, is the most prevalent cause of secondary erythrocytosis. This can be caused by chronic obstructive pulmonary disease (COPD), high-altitude living, or particular heart or lung issues. Other variables that lead to erythrocytosis include kidney illness, tumors, and the use of erythropoietin-stimulating medicines. Understanding the underlying etiology of erythrocytosis is critical for accurate diagnosis and treatment.


Many erythrocytosis symptoms are caused by your blood flowing more slowly than usual. Among these signs are:

  • Double vision
  • Headaches
  • Confusion
  • High blood pressure
  • Nosebleeds
  • Itching
  • Weakness
  • Tiredness


Doctors inquire about any medications that may induce erythrocytosis. They assess the amount of oxygen and erythropoietin in the blood. A high erythropoietin level is frequently adequate for clinicians to identify secondary erythrocytosis. If the level is low, other tests for primary erythrocytosis (polycythemia vera) will be performed.

Other specialized tests are sometimes performed, especially when doctors seek to discover a rare cause of erythrocytosis. Tests for a hormone problem or a concealed tumor causing other symptoms may be included.

Congenital erythrocytosis is typically identified when a person exhibits symptoms at a young age or has erythrocytosis in family members. Doctors may utilize genetic testing for erythrocytosis diagnosis in addition to blood tests to pinpoint the specific cause.


The underlying etiology of the illness mainly determines erythrocytosis treatment. Primary erythrocytosis management, caused by a genetic mutation such as the JAK2 mutation, often includes regular monitoring of hematocrit levels and therapeutic phlebotomy. This procedure removes excess red blood cells to reduce blood viscosity and the risk of complications such as blood clots.

Secondary erythrocytosis, typically caused by external factors such as prolonged hypoxia, necessitates addressing the underlying cause. This may entail treating the underlying problem, such as lung or heart disease, or changing lifestyle variables, such as quitting smoking and staying hydrated.

Medicines such as hydroxyurea may be used to reduce red blood cell synthesis in some circumstances. After a thorough review of the patient’s individual circumstances and medical history, a healthcare practitioner should decide the best treatment strategy for erythrocytosis.

When To See A Doctor

Consult a primary care physician if you have symptoms such as exhaustion, dizziness, or shortness of breath, have abnormal blood test results, or have risk factors such as a family history or chronic conditions. Seek medical advice if you use drugs that influence red blood cell formation or reside at high altitudes. Early identification and management are critical to treat the underlying causes and limit potential complications.


This information is intended for educational purposes only and should not be considered a substitute for professional medical advice. If you have concerns about erythrocytosis or any other medical condition, please see a doctor for an accurate diagnosis and personalized treatment suggestions.