Polycythemia vera

Polycythemia vera (pol-e-sy-THEE-me-uh VEER-uh) is a type of blood cancer. It causes the bone marrow to make too many red blood cells. These extra cells thicken the blood, slowing its flow. This may cause serious problems, such as blood clots.

Polycythemia vera is rare. It comes on slowly. You might have it for years without knowing. Often the condition is found during a blood test done for another reason.

Without treatment, polycythemia vera can be life-threatening. But proper medical care can help ease symptoms and complications of this disease.

Many people with polycythemia vera don't notice symptoms. Some people get symptoms such as headache, dizziness, tiredness and blurred vision.

Clearer symptoms of polycythemia vera include:

• Itchiness, mostly after a warm bath or shower.
• Numbness, tingling, burning or weakness in the hands, feet, arms or legs.
• A feeling of fullness soon after eating.
• Bloating or pain in the left upper stomach area due to an enlarged spleen.
• Unusual bleeding, such as a nosebleed or bleeding gums.
• Painful swelling of one joint, often the big toe.
• Shortness of breath and trouble breathing when lying down.
• Bone pain.

Make an appointment with your healthcare professional if you have symptoms of polycythemia vera.

Polycythemia vera happens when a change in a gene causes a problem with making blood cells. The body typically controls the number of each of the three types of blood cells. These are red blood cells, white blood cells and platelets. But in polycythemia vera, the bone marrow makes too many of some of these blood cells.

The cause of the gene change in polycythemia vera is unknown. But it's not passed through families.

Polycythemia vera can happen at any age. But it's more common in adults over age 60. Men are more likely to get polycythemia vera than women are.

Possible complications of polycythemia vera include:

• Blood clots. Increased blood thickness, decreased blood flow and atypical platelets raise the risk of blood clots. Blood clots can cause a stroke or a heart attack. Or clots can block an artery in the lungs or a vein deep within a leg muscle or in the belly.
• Enlarged spleen. The spleen helps the body fight infection. It also filters waste, such as old or damaged blood cells. The extra blood cells that occur with polycythemia vera make the spleen work harder. That causes it to enlarge.
• Problems due to high levels of red blood cells. Too many red blood cells can lead to other complications. These include open sores on the inside lining of the stomach, upper small intestine or esophagus, called peptic ulcers, and swelling of the joints, called gout.
• Other blood disorders. In rare cases, polycythemia vera can lead to other blood diseases. These include a disorder in which scar tissue replaces bone marrow, a condition in which stem cells don't mature or work as they should, and cancer of the blood and bone marrow, called acute leukemia.