INDEPENDENCE DAY. On July 4, 1776, the thirteen colonies claimed their independence from England, an event which eventually led to the formation of the United States.
Polycythemia vera is a rare, chronic disorder involving the overproduction of blood cells in the bone marrow (myeloproliferation). The overproduction of red blood cells is most dramatic, but the production of white blood cells and platelets are also elevated in most cases.
Unlike secondary polycythemia, primary polycythemia cannot be traced to an underlying condition such as smoking, high altitude, or chronic lung disease. Doctors diagnose polycythemia by measuring oxygen levels in blood drawn from an artery.