Complications

Possible complications of polycythemia vera include:

• Blood clots. Increased blood thickness and decreased blood flow, as well as abnormalities in your platelets, raise your risk of blood clots. Blood clots can cause a stroke, a heart attack, or a blockage in an artery in your lungs or a vein deep within a leg muscle or in the abdomen.
• Enlarged spleen. Your spleen helps your body fight infection and filter unwanted material, such as old or damaged blood cells. The increased number of blood cells caused by polycythemia vera makes your spleen work harder than normal, which causes it to enlarge.
• Problems due to high levels of red blood cells. Too many red blood cells can lead to a number of other complications, including open sores on the inside lining of your stomach, upper small intestine or esophagus (peptic ulcers) and inflammation in your joints (gout).
• Other blood disorders. In rare cases, polycythemia vera can lead to other blood diseases, including a progressive disorder in which bone marrow is replaced with scar tissue, a condition in which stem cells don't mature or function properly, or cancer of the blood and bone marrow (acute leukemia).