Polycythemia vera (PV) can be a silent disease. You may have no symptoms, and then find out during a routine blood test that your red blood cell counts are too high. PV is considered a type of blood cancer due to the abnormal production of red blood cells.

Knowing the symptoms of this rare blood disease is one way to get a diagnosis and receive treatment early.

Many of the symptoms of PV are caused by too many red blood cells, making the blood thicker than normal. Thicker blood has a difficult time moving through blood vessels. This limits the amount of oxygen that can get to organs and tissue.

Some possible signs and symptoms of PV include:

These symptoms can also be mistaken for other conditions. As PV progresses, more serious problems can occur, including:

PV can become life-threatening when a blood clot cuts off blood and oxygen supply to vital organs. This can cause:

  • strokes
  • heart attacks
  • intestinal injuries
  • pulmonary embolisms, caused by blood clots in the blood vessels of the lung

For some people, thrombosis is the first symptom of PV. Thrombosis is when a blood clot forms in either your veins or arteries. Veins are blood vessels that carry blood to your heart. Arteries are blood vessels that carry oxygen-rich blood away from your heart to other parts of your body.

The symptoms of thrombosis depend on the location of the clot. If it forms in the blood vessels of your brain, it can lead to a stroke. If it forms in the blood vessels of your heart, it can lead to a heart attack.

Deep vein thrombosis (DVT) occurs when a blood clot forms in your veins. The most common place for a DVT to develop is in the legs, but it can occur in veins of the arms, abdomen, and pelvis too. A pulmonary embolism occurs when a blood clot happens in your lungs, often from a DVT moving to the lungs from somewhere else in the body.

PV can cause an increase of uric acid. This substance is released when red blood cells are broken down. This can contribute to:

About 15 percent of those with PV develop myelofibrosis. Myelofibrosis is serious bone marrow scarring in which scar tissue replaces your bone marrow. This scarring means that you can no longer produce healthy, properly functioning blood cells.

Myelofibrosis may contribute to an enlarged liver and spleen. Your doctor may recommend a bone marrow transplant for severe cases of PV.

After many years of PV, some people can develop another type of blood cancer known as leukemia. It’s estimated that 10 percent of people who’ve had PV more than 10 years will develop acute myeloid leukemia. Another type of leukemia, acute lymphoblastic leukemia, can also occur but is more rare. These conditions require treatments that focus on both PV and the specific type of leukemia.

The key to effectively managing PV is getting treatment early. This can reduce the risk of serious complications, particularly thrombosis.

A variety of treatment options are also available for other symptoms and conditions associated with PV. Talk to your doctor about which medications and treatment options are best for you.