If you have a high platelet count and your GP suspects that you have PV, he or she will refer you to a haematologist, a doctor who specialises in treating blood diseases. The haematologist will look for clues to the diagnosis of PV by examining you and asking you about your health, medications, lifestyle and family history.

The haematologist uses several tests to confirm the diagnosis of PV and to understand your condition. The first of these tests is usually a red cell mass study. This study shows whether or not there is a raised red cell mass. Asample of your blood is taken in the Nuclear Medicine department. The blood sample is treated with a radioactive dye and returned to you, then the blood with the radioactive dye dilutes in your body.

The haematologist will take another blood sample to determine if there is a raised red cell mass (absolute erythrocytosis) or a normal red cell mass (apparent erythrocytosis).

In addition to the red cell mass study, you may need the other tests to determine the cause of the elevated red blood cell count, including:

• Liver, kidney and urine tests.
• Iron, folate and vitamin B 12 measurements.
• Measurement of oxygen levels in the blood.
• Chest x-ray and abdominal ultrasound.

These additional tests help your haematologist understand your condition in more detail:

• A bone marrow biopsy (BMB)
• Lung function test
• Blood test measuring haemoglobin binding to oxygen
• An ECG (echocardiogram) to examine the heart
• Genetic testing of the erythropoietin receptor
• A sleep study
  
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