What causes polycythaemia vera?
The initial process is the same as for other causes of a high red cell count (erythrocytosis). • A blood test will show any increase in red cells numbers. The blood test should then be repeated to confirm the abnormal result. You will then be asked about your medical history and have a physical examination. • A red cell mass study is usually then needed to see if you have an absolute erythrocytosis (raised red cell mass, normal plasma volume). The study is often carried out in a hospital’s nuclear medicine department and involves mixing weak dyes with a sample of your blood and then returning it to your body. The dyed cells distribute themselves among your red cells, making it possible to calculate what the total mass of red cells must be. • Other diagnostic tests that may be performed include blood tests for kidney function, liver function and levels of iron, folic acid, vitamin B12 and oxygen in the blood, urine test, chest X-ray and ultrasound of the abdomen. The diagnosis of PV is