Polycythemia
Definition and Overview
Polycythemia is a condition characterized by an increased number of red blood cells in the blood. This increase can result in thickening of the blood, slowing its flow and potentially leading to clotting. Polycythemia can be primary, caused by changes in the body's red blood cell production, or secondary, resulting from factors outside the bone marrow. It can also be classified as polycythemia vera, a rare type of blood cancer, or secondary polycythemia, often caused by long-term exposure to low oxygen levels.
Causes
Primary polycythemia, also known as polycythemia vera, is caused by a mutation in the JAK2 gene. This mutation results in the bone marrow producing too many red blood cells. The exact cause of this mutation is unknown, but it is not inherited. Secondary polycythemia can be caused by various conditions that increase the body's production of erythropoietin, a hormone that stimulates red blood cell production. These conditions can include chronic lung diseases, certain tumors, and living at high altitudes.
Symptoms
Symptoms of polycythemia can vary greatly, but often include fatigue, weakness, shortness of breath, and headaches. More severe symptoms can include chest pain, dizziness, and an enlarged spleen. In some cases, individuals with polycythemia may experience blood clots, which can lead to serious complications such as stroke or heart attack.
Diagnosis
Polycythemia is typically diagnosed through blood tests that measure the number of red blood cells and the level of hemoglobin, a protein in red blood cells that carries oxygen. In some cases, a bone marrow biopsy may be performed to confirm the diagnosis and determine the cause. Genetic testing may also be used to identify the JAK2 mutation associated with polycythemia vera.
Treatment
Treatment for polycythemia aims to reduce the number of red blood cells in the blood and prevent complications. This can be achieved through phlebotomy, a procedure in which blood is drawn from the body to decrease its volume. Medications may also be used to decrease blood cell production or to treat symptoms. In some cases, low-dose aspirin may be recommended to reduce the risk of blood clots.
Prognosis
The prognosis for individuals with polycythemia varies depending on the underlying cause and the individual's overall health. With appropriate treatment, many individuals with polycythemia can manage their symptoms and live a normal lifespan. However, complications such as blood clots can pose serious risks and may require additional treatment.
See Also
References
1. Tefferi A, Barbui T. Polycythemia vera and essential thrombocythemia: 2019 update on diagnosis, risk-stratification and management. American Journal of Hematology. 2019;94(1):133-143. [1] 2. McMullin MF, Harrison CN, Ali S, et al. A guideline for the diagnosis and management of polycythaemia vera. A British Society for Haematology Guideline. British Journal of Haematology. 2019;184(2):176-191. [2] 3. Vannucchi AM. Management of polycythemia vera. Hematology American Society of Hematology Education Program. 2011;2011:174-181. [3]