Polycythemia is a type of blood cancer that causes an increase in the number of red blood cells, leading to a thickening of the blood. Symptoms include headache, dizziness, fatigue, and shortness of breath. The condition can be caused by a genetic mutation or an overproduction of erythropoietin, a hormone that stimulates red blood cell production.

Treatment options include phlebotomy (removal of blood), chemotherapy, or radiation therapy. In some cases, medication may also be used to control the overproduction of erythropoietin. Early diagnosis and treatment are important to manage the symptoms and prevent complications.

Note: This is a general description. Please take professional health advice.