While it’s never pleasant to think you may have a serious disease it’s important that you find out early on. Some diseases are so subtle and asymptomatic you need tests to discover them. Polycythemia vera is considered a rare disease with about 2 in every 100,000 people having the disease. It usually develops slowly, and you might have it for years without knowing. Often the condition is found during a blood test done for another reason. Do you have Polycythemia Vera?