When blood is too thick, it clots more easily, and the potential exists for blockage of the blood flow through the arteries and veins, according to the National Heart, Lung and Blood Institute. This may trigger a heart attack or stroke. Polycythemia vera is a condition in which the body produces too many red blood cells, causing thickening of the blood and increasing the possibility that clotting occurs.
The NHLB explains that polycythemia vera prevents the blood from flowing as quickly through the body as it normally does, which means the organs don't get as much oxygen as they need. Problems including severe pain or discomfort in the chest or heart failure may develop.
WebMD notes that blood clots are necessary when it comes to stopping bleeding, but abnormal blood clots cause heart attacks, strokes and other serious medical problems, such as deep venous thrombosis.
The NHLB states that polycythemia vera may not show visible symptoms for years. Many doctors find it while performing routine blood tests. WebMD mentions a few medications, such as aspirin, brilinta, effient, and clopidogrel, that make blood clots more or less likely to occur. The oral drugs warfarin, eliquis, pradaxa, and Xarelto also make blood clots less likely. Heparin provides an intravenous or injectable option to prevent blood clot formation.