Polycythemia vera (PV) is a bone marrow disease that leads to an abnormal increase in the number of blood cells. The red blood cells are mostly affected.
PV is a disorder of the bone marrow. It mainly causes too many red blood cells to be produced. The numbers of white blood cells and platelets may also be higher than normal.
PV is a rare disorder that occurs more often in men than in women. It is not usually seen in people under age 40. The problem is often linked to a gene defect called JAK2V617F. The cause of this gene defect is unknown.
With PV, there are too many red blood cells in the body. This results in very thick blood, which can't flow through small blood vessels normally, leading to symptoms such as:
The health care provider will perform a physical exam. You may also have the following tests:
PV may also affect the results of the following tests:
The goal of treatment is to reduce the thickness of the blood and prevent bleeding and clotting problems.
A method called phlebotomy is used to decrease blood thickness. One unit of blood (about 1 pint, or 1/2 liter) is removed each week until the number of red blood cells drops. The treatment is continued as needed.
Medicines that may be used include:
Taking aspirin to reduce the risk of blood clots may be an option for some people. But, aspirin increases the risk of stomach bleeding.
Ultraviolet-B light therapy can reduce the severe itching some people experience.
PV usually develops slowly. Most people do not have symptoms related to the disease at the time of diagnosis. The condition is often diagnosed before severe symptoms occur.
Complications of PV may include:
Call your provider if symptoms of PV develop.
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.