Polycythemia

Polycythemia is a medical condition characterized by an increased concentration of red blood cells (erythrocytes) in the blood. This increase can be a response to an event such as living at high altitudes or a symptom of an underlying disease.

Composition of Blood

Classification

Polycythemia vera, blood smear

Polycythemia can be classified into primary and secondary types.

Primary Polycythemia

Primary polycythemia, also known as polycythemia vera, is a chronic myeloproliferative disorder where overproduction of red blood cells occurs due to abnormality in the bone marrow. This is often due to mutations in the JAK2 gene.

Secondary Polycythemia

Secondary polycythemia is caused by either natural or artificial factors that induce erythropoietin production, such as living at high altitudes, chronic hypoxia, or tumors.

Pathophysiology

In polycythemia, the increase in the volume of red blood cells leads to an increase in blood viscosity and total blood volume, potentially leading to hyperviscosity syndrome. This condition can result in complications such as thrombosis and can put strain on the heart, leading to heart failure.

Clinical Features

Symptoms of polycythemia may include fatigue, headache, itchiness, bone pain, joint pain, dizziness, abdominal discomfort, and an enlarged spleen. In severe cases, stroke or heart attack may occur.

Diagnosis and Treatment

Diagnosis is based on a combination of physical examination, medical history, and laboratory tests including a complete blood count and bone marrow biopsy. Treatment can include phlebotomy, medications to reduce blood cells production, or treatments to alleviate symptoms.

References

Polycythemia Resources
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