Polycythemia vera is a disease where too many red blood cells are made in the bone marrow, which makes the blood thick. White blood cells and platelets may also increase and these extra blood cells tend to collect in the spleen causing it to swell. The increased number of blood cells can cause bleeding problems and form clots causing serious health problems such as stroke or heart attack. In patients older than 65 years, the risk of stroke and heart attack is higher, and polycythemia vera is more likely to become acute myeloid leukemia or chronic idiopathic myelofibrosis.
Early symptoms of polycythemia vera don’t often appear. The disease is sometimes found during routine blood tests. Symptoms may occur as the number of blood cells increases.
Symptoms may include: