What is polycythemia?

Polycythemia is a blood condition in which the bone marrow makes excess blood cells, primarily red blood cells, but also platelets and white blood cells. The extra cells cause a thickening of the blood, which increases the risk of blood clotting, in turn potentially causing strokes, heart attacks, and other complications. While the exact cause of polycythemia is not known, genetic changes are thought to be related to its development.

Genetic polycythemia, referred to as polycythemia vera, develops slowly and is generally seen in older adults. It is rare in young adults and children. Although it is the result of genetic mutations or changes in particular genes, these genetic changes are acquired during an individual’s lifetime and are generally not passed from parents to their children. Polycythemia is more common in adults over 60 years of age, and about one in every 200,000 people is diagnosed each year with the condition (Source: NHLBI).

In the early stages of polycythemia, symptoms may be mild and include flushed face, dizziness, and impaired senses. In more severe cases, thrombosis (blood clotting) may occur, leading to severe symptoms.

In secondary polycythemia, long-term oxygen deprivation, such as from chronic smoking or long periods spent at high altitudes, causes increased production of red blood cells and resultant blood thickening. This form of polycythemia often resolves once the cause of oxygen deprivation is addressed. In all cases of polycythemia, treatment by periodic blood draws or medications to reduce the number of blood cells is generally effective, although there is no cure for the condition.

While polycythemia is rare, generally treatable, and usually mild, serious complications such as heart attack or stroke can occur if left untreated. Seek immediate medical care (call 911) for any sudden symptoms of heart attack or stroke, such as sudden numbness, weakness, confusion, vision problems, or chest pain.

Polycythemia may also lead to less severe symptoms, such as difficulty breathing when lying down or excessive bleeding. Seek prompt medical care if these symptoms persist, as early diagnosis and intervention are critical to preventing more severe symptoms.


What are the symptoms of polycythemia?

Symptoms of polycythemia include symptoms related to excessive thickening of the blood, such as reddened face, bleeding of the gums, dizziness, and itchiness. Polycythemia can also affect the eyes and ears, leading to blurred vision or tinnitus. In more serious cases of polycythemia, thrombosis (clotting) can develop, leading to heart attack or stroke.

Common symptoms of polyc... Read more about polycythemiasymptoms


What causes polycythemia?

The exact causes of polycythemia are not known. There is evidence, however, that mutations (changes) in specific genes are related to the development of the disease. These mutations occur during an individual’s lifetime and are not passed on from parents to their children. Only in very rare cases is polycythemia inherited.

A second type of polycythemia, called secondary polycythem... Read more about polycythemiacauses


How is polycythemia treated?

Polycythemia is treated by thinning the blood to keep clots from forming. This can be performed by periodic blood draws to reduce red blood cell count. In some cases, medications may be administered to suppress the bone marrow and reduce blood cell counts, including hydroxyurea and interferon. Aspirin may also be used to prevent blood clots, although this is less common due to an increased risk... Read more about polycythemiatreatments

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Sep 20, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.