Polycythaemia vera

What is it?

Polycythaemia vera (PV or primary polycythaemia) is a chronic condition causing an anomaly in the bone marrow, leading to an uncontrolled production of red blood cells.

Red blood cell overproduction can make the blood thicker than it should be, making blood circulation much harder. Polycythaemia vera is hence associated with a higher risk of blood clots and thrombosis.

It is an idiopathic condition whose underlying causes are unknown. This condition is more common for people in their twenties, affecting both men and women.


Polycythaemia vera is potentially very dangerous, as it can result in thrombosis and embolisms, as well as facilitating the occurrence of leukaemia (myelofibrosis). The average life expectancy after diagnosis is a further 20 years.

What are the symptoms?

The first symptoms of PV are:

  • Weakness and fatigue;
  • Headaches;
  • Confusion and stupor;
  • Shortness of breath;
  • Night sweats;
  • Running a mild fever;
  • Symptoms of a blood clot, such as pain and swelling localised in the affected area and the obstructed vein being visible.

How is it diagnosed?

During a physical examination, the specialist will look for a potentially enlarged spleen and altered breathing, abnormalities in cardiovascular and vascular circulation, kidney functionality, liver and eye functioning, and neurological and gastrointestinal anomalies.

Furthermore, a blood test will be carried out to confirm whether or not you have an elevated blood cell count.

What causes it?

Although the root cause for PV is not clear yet, it has been observed that almost every person affected by polycythaemia vera has a mutation in the JAK2 gene (which causes an overproduction of haemocytes).

In more rare cases, PV can be inherited: in that case, it is known as primary familial polycythaemia.

How is it treated?

The most common treatments for polycythaemia vera are:

  • Phlebotomy (removal of blood from the body): it involves removing roughly half a litre of blood on alternate days, until your blood test results are better. This treatment can be repeated after a few months as needed;
  • Taking medications to reduce the red blood cell count.

Treatment aims to slow down the progression of PV, as the condition cannot be cured.

Which doctor should I talk to?

A specialised haematologist can help you confirm a diagnosis and determine which treatment works best for you.

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