PV is a type of blood cancer. It belongs to a group of conditions that affect the blood called myeloproliferative neoplasms (MPN).

PV happens when your body makes too many red blood cells. This causes your blood to become thicker than normal.

Find out more about PV and its causes

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You may not experience any symptoms at all if you have PV, even once you’re diagnosed. Many people with PV are diagnosed after a routine blood test.

Common symptoms include headaches, blurred vision and skin changes.

Find out more about the symptoms and diagnosis of PV

In PV, the goal of treatment is to make sure your risk of developing blood clots is as low as possible. The type of treatment you have will depend on certain factors, including your age and how your blood cells are affected.

Find out about treatment and side effects for PV

With proper monitoring and treatment, most people with PV have a normal lifespan and quality of life.

Find out more about the prognosis for PV