Now that is interesting - my mother had polycythemia vera and used to joke that she would give her excess rbc's to me! She was treated for it the last 10 years or so of her life (She died in 2003 at age 90 of a stroke). One doctor told her that it was more often found among people who had lived at high altitudes. She was raised in the mountains. Maybe my HCL has a hereditary link?