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Medical Author:

Siamak T. Nabili, MD, MPH

Siamak T. Nabili, MD, MPH

Dr. Nabili received his undergraduate degree from the University of California, San Diego (UCSD), majoring in chemistry and biochemistry. He then completed his graduate degree at the University of California, Los Angeles (UCLA). His graduate training included a specialized fellowship in public health where his research focused on environmental health and health-care delivery and management.

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Medical Editor:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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In this Article

• What is polycythemia?
• What are normal ranges of hematocrit, red cell counts, and hemoglobin?
• What causes polycythemia?
• What are the causes of primary polycythemia?
• What are the common causes of secondary polycythemia?
• Can other sources of erythropoietin (EPO) cause polycythemia?
• What is relative polycythemia?
• What is stress polycythemia?
• What are the risk factors for polycythemia?
• What are the symptoms of polycythemia?
• When should I see a doctor about polycythemia?
• How is polycythemia diagnosed?
• What is the treatment for polycythemia?
• What are the complications of polycythemia?
• Can polycythemia be prevented?
• What is the outlook (prognosis) for polycythemia?
• Polycythemia At A Glance
• Patient Comments: Polycythemia (High Red Blood Cell Count) - Cause
• Patient Comments: Polycythemia - Experience
• Patient Comments: Polycythemia - Symptoms
• Find a local Hematologist in your town
• Polycythemia (High Red Blood Cell Count) Index

Potential complications of polycythemia vera is increased levels of circulating red blood cells, which increases the thickness or viscosity of the blood. This can be associated with higher risk of thrombus or clot formation leading to strokes, heart attacks, pulmonary embolism, and possibly death.

Another complication of polycythemia vera is the potential transformation into a blood cancer (leukemia), excessive bleeding (hemorrhage), or clotting problems.

Because of high turn over of blood cells in polycythemia, the excretion of the by products of red blood cell degradation may over burden the kidneys and result in kidney dysfunction, kidney stones, and gout.

Complications of secondary polycythemia are typically related to those of the underlying disease. For example, chronic hypoxia from severe lung disease may be complicated by right sided heart failure and pulmonary hypertension. Chronic heart failure can lead to generalized swelling or edema (anasarca), low blood pressure, kidney dysfunction, and poor functional status.

In neonatal (infant) polycythemia, increased blood thickness or viscosity can affect several organs due to poor blood flow. As a result, kidney dysfunction, intestinal problems, increased blood pressure in the lungs, and hypoxia may ensue.