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HealthInfo West Coast-Te Tai Poutini

Primary polycythaemia (high red blood cells)

Your blood is made of white blood cells, red blood cells, platelets, and plasmaWhat is primary polycythaemia?

Primary polycythaemia, also called primary polycythaemia vera or PV, is a condition that causes a high red blood cell count. Red blood cells contain a substance called haemoglobin, which carries the oxygen around your body.

Most people with polycythaemia remain well, but they do have a higher risk of getting blood clots. These can lead to deep vein thrombosis (DVT), pulmonary embolism, strokes, heart attacks, or loss of the blood supply to a toe or finger.

Sometimes, after many years people with ET can develop other blood problems, such as anaemia, scarring of their bone marrow (a condition called myelofibrosis), or even leukaemia.

Do I need any treatment?

You are much less likely to get a blood clot if you have treatment to lower your haemoglobin and red blood cells to the normal level. There are two types of treatment: regularly removing blood (called blood letting or venesection), and drug treatment, usually with hydroxyurea (see below).

We also advise patients to take low-dose aspirin, as this also reduces the risk of blood clots. However, some people can't take aspirin because it irritates their stomach.

How and when does blood letting happen?

If you have blood removed, it may be done by your general practice team or at Grey Base Hospital.

You will have just under half a litre of blood taken, much as if you were a blood donor. It's a very straightforward procedure, and only takes about half an hour. Usually you'll have this done every few months.

How will I get my hydroxyurea?

If you need treatment it will be with hydroxyurea, which you will have received full information about.

You will take a capsule of hydroxyurea every morning. It doesn't usually cause any side effects, but very rarely it might cause nausea (feeling sick).

Hydroxyurea slows down your bone marrow so you don't make as many platelets. If you take too much, the number of red and white blood cells and platelets in your blood (called your blood count) will be too low. So you will need to get your blood count checked every couple of months or so, even if you've been taking the same dose for a while. Most people stay on the same dose of hydroxyurea for many years, perhaps needing only small changes.

Occasionally people get skin reactions, particularly painful ulcers in their lower legs. If this happens to you, you will have to stop taking hydroxyurea and try another treatment.

Hydroxyurea will make you more sensitive to the sun, so make sure you cover up and wear sunscreen if you go outside on sunny days.

Who will care for me?

If you are well and on regular venesection or a stable dose of hydroxyurea, you will mostly see your own GP, which is much more convenient than coming into the hospital. Your GP will arrange to get your blood checked regularly, and will let you know if you need any changes in treatment.

You will still need to see the hospital blood specialist every one to two years, to check how you are going.

If anything new happens that worries you, talk to your GP or your blood specialist. If your GP is worried about anything they will ask your blood specialist for further advice. If this happens, you may need to see the hospital specialist earlier than usual.

Information provided by the Canterbury DHB. Adapted by the West Coast DHB. Page created November 2015.

See also:

Understanding your complete blood count results

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