Polycythemia vera (PV) is a benign but chronic and progressive form of blood cancer. The earlier the diagnosis, the more easily it can be treated and the less likely you’re going to have any serious complications or risks.

Diagnosing PV

The discovery of the JAK2 genetic mutation, JAK2 V617A, has helped in diagnosing PV. About 95 percent of those who have PV also have this genetic mutation.

For those with the JAK2 mutation, cells keep reproducing which leads to your blood thickening. This restricts the flow of blood to your organs and the rest of your body and can also result in blood clots.

A regular blood test can show if your blood has thickened or if your blood count levels are too high. Early symptoms such as headaches, dizziness, or shortness of breath may be a reason to make an appointment and to have a blood test done.

If your doctor thinks you have PV, you’ll be referred to a hematologist. This blood specialist will determine your treatment method. This usually consists of periodic phlebotomy, or blood drawing, along with a daily aspirin.


When PV is detected in a more advanced stage, you may experience complications.


Thrombosis is the clotting of blood in your arteries or veins. Symptoms of a blood clot depend on where the clot has formed. A clot in your:

  • brain can cause a stroke
  • heart would result in a heart attack or other coronary episode
  • lungs would cause a pulmonary embolism
  • muscles would be a deep vein thrombosis

Enlarged Spleen

Your spleen is located in the upper left part of your abdomen. One of its jobs is to filter worn out blood cells from the body. Feeling bloated or full are two symptoms of PV triggered by an enlarged spleen.

Your spleen becomes enlarged while trying to filter out the excessive number of blood cells that are being created in your bone marrow. If your spleen doesn’t return to its normal size with standard PV treatments, it may have to be removed.

High Levels of Red Blood Cells

The increase of red blood cells can lead to other problems. These include peptic ulcers, joint inflammation, and sores in your upper small intestine or esophagus. Your hematologist will suggest ways to treat these symptoms.


Myelofibrosis, also called the “spent phase” of PV, affects 15 percent of those diagnosed with PV. During this advanced stage, your bone marrow no longer produces cells that are healthy or function properly. Instead your bone marrow is replaced with scar tissue.

Periodic blood transfusions may be successful in keeping blood cells at an acceptable level. When that doesn’t work, a stem cell transplant might be considered to eliminate the disease.


Advanced PV can lead to acute leukemia, or cancer of the blood and bone marrow. This is a rare complication.

Complications from Treatments

There are also certain complications and side effects that can be caused by treating PV.

You may begin to feel tired or fatigued after a phlebotomy, especially if you’re having this procedure frequently. Your veins may also become damaged from the procedure.

In some cases, a low-dose aspirin regimen can lead to bleeding.

Hydroxyurea, which is a form of mild chemotherapy, can lower your blood count too much. In rare cases, it can cause mouth or skin sores. Ruxolitinib (Jakafi), a treatment for myelofibrosis and polycythemia vera, can also suppress your blood count too much.

If you experience any of these side effects, talk to your medical team. You and your hematologist will work together to find the right treatment.