The procedure is usually carried out with sedation as well as local anaesthetic. It may be necessary to have other tests such as lung function tests to rule out other possible causes of polycythaemia and confirm that the diagnosis is polycythaemia vera. The simplest and most rapid way to reduce the number of red cells is blood-letting. This is called venesection or phlebotomy. This may mean taking blood as often as once a week initially.
Longer intervals become usual as the patient becomes moderately iron-deficient.
This tends to keep the PCV lower than it would otherwise be. The main limitation of this treatment is that it does not reduce the platelet count. If the platelet count is too high, a more appropriate form of treatment is to use an oral drug such as hydroxyurea or injections of interferon. The use of small daily doses of aspirin may also help to prevent blood clots. Unfortunately there is no treatment which will cure polycythaemia vera.