Polycythemia vera is an abnormal increase in the number of blood cells (primarily red blood cells) produced by the bone marrow.

Primary polycythemia; Polycythemia rubra vera; Myeloproliferative disorder; Erythremia; Splenomegalic polycythemia; Vaquez's disease; Osler's disease; Polycythemia with chronic cyanosis - Myelopathic polycythemia; Erythrocytosis megalosplenica; Cryptogenic polycythemia

Polycythemia vera is a disorder of the bone marrow. It causes too much production of white blood cells, red blood cells, and platelets.

It is a rare disease that occurs more often in men than women, and is rare in patients under age 40. The exact cause is unknown.

• Breathing difficulty when lying down
• Dizziness
• Fullness in the left upper abdomen
• Headache
• Itchiness, especially after a warm bath
• Red coloring, especially of the face
• Shortness of breath
• Symptoms of phlebitis

Note: Symptoms are due to increased blood thickness and clotting.

Other symptoms that may occur with this disease:

• Bluish skin discoloration
• Fatigue
• Red skin spots
• Vision problems

The health care provider will perform a physical exam. Tests that may be done include:

• Bone marrow biopsy
• Blood volume
• Chemistry panel
• Complete blood count with differential
• Erythropoietin level
• Genetic test
• Vitamin B12 level

This disease may also affect the results of the following tests:

• ESR
• Lactate dehydrogenase
• Leukocyte alkaline phosphatase
• Platelet aggregation test
• Serum uric acid

The goal of treatment is to reduce the thickness of the blood and prevent bleeding and clotting.

A method called phlebotomy is used to decrease blood thickness. One pint of blood is removed weekly until the hematocrit level is less than 45, then therapy is continued as needed.

Occasionally, chemotherapy (specifically hydroxyurea) may be given to suppress the bone marrow. Interferon may also be given in an attempt to lower blood counts. A medicine called anegrelide may be given to lower platelet counts.

The use of blood thinners (such as aspirin) is controversial because it may cause stomach bleeding. However, it does prevent blood clots.

The disease usually develops slowly. Most patients do not experience any problems related to the disease after being diagnosed.

The following complications occur in a small number of patients:

• The abnormal bone marrow cells may begin to grow uncontrollably in some patients, leading to the development of acute myelogenous leukemia (AML).
• The bone marrow may develop a scarring condition called myelofibrosis.This condition may lead to dangerously low levels of white blood cells, red blood cells, and platelets.

Patients with polycythemia vera are also more likely to form blood clots that can cause strokes or heart attacks. Some patients may experience abnormal bleeding because their platelets are abnormal.

• Bleeding from the stomach or other parts of the intestinal tract
• Gout
• Heart failure
• Leukemia
• Myelofibrosis
• Peptic ulcer disease
• Thrombosis (blood clotting, which can cause stroke or heart attack)

Call your health care provider if symptoms of polycythemia vera develop.

Tefferi A. Polycythemias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 172.