Polycythemia意思
"Polycythemia" is a medical term that refers to a condition characterized by an abnormally high red blood cell count in the blood. This increase in red blood cells can lead to a higher than normal hematocrit (the proportion of red blood cells in the blood) and hemoglobin (the protein in red blood cells that carries oxygen) levels.
There are several types of polycythemia:
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Polycythemia Vera (PV): This is a chronic blood disorder that is considered a type of myeloproliferative neoplasm. It is characterized by an overproduction of red blood cells, but it can also involve the overproduction of white blood cells and platelets. PV is a clonal disorder, meaning it arises from a single mutated cell.
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Secondary Polycythemia: This type of polycythemia is caused by external factors such as high altitude, where the body compensates for the lower oxygen levels by producing more red blood cells. It can also be caused by certain diseases, such as lung or kidney disease, which can lead to anemia and stimulate the bone marrow to produce more red blood cells.
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Iatrogenic Polycythemia: This occurs when the increase in red blood cells is due to medical treatments, such as receiving multiple blood transfusions without proper blood loss.
Symptoms of polycythemia can include fatigue, weakness, headaches, dizziness, itching, and visual disturbances. However, not all individuals with polycythemia experience symptoms.
Polycythemia can lead to complications such as blood clots, heart problems, and an increased risk of stroke. Treatment may involve phlebotomy (removing blood to reduce the hematocrit level), medications to reduce the production of red blood cells, and in some cases, more aggressive treatments like chemotherapy or stem cell transplantation.