What is a venesection?


Venesection is removing blood from one’s blood circulation, usually through a puncture in the arm, for blood analysis or treatment for certain blood disorders. The aims of the treatment are to decrease iron in the blood or decrease red blood cells.


Haemochromatosis, polycythemia and porphyria cutanea tarda are 3 disorders which require the treatment of venesection.




Haemochromatosis is caused by genetic disorders or from a variety of factors including alcoholism. In this disorder, excess iron is absorbed into the body from the diet – over and above the body’s needs. Over time, iron deposits build up in the body tissues: heart, liver, pancreas, pituitary gland and joints. This leads to liver scarring (cirrhosis), liver cancer, arthritis, early menopause, loss of libido, impotence, heart problems such as heart failure.



By giving blood (and hence reduces the iron load) through venesection, is one of the established ways to prevent the potential damage that is done to organs and joints throughout the years.





Polycythemia is a blood disorder where the body makes too many red blood cells. Thickening of the blood cells, increases the chance of blood clots forming. This can lead to strokes, heart attacks or clots in the lungs (pulmonary embolism).


Venesection, in this instance, is used to reduce the number of blood cells by decreasing the blood volume. Treatment is continued until the concentration of blood cells in blood (haematocrit) reaches a normal level.

orphyria cutanea tarda


It is a metabolic disease that involves a light sensitive chemical being deposited in the skin, leading to skin and tissue damage.


The condition is caused by deficiency of an enzyme, which forms the light sensitive chemical. Its formation is dependent on iron in the liver, hence the therapeutic need to reduce iron load in the liver.


Venesection is performed regularly with the aim of reducing blood iron level to the lower limit of normal.





At our clinics at Top Health Doctors, we take a comprehensive history and assess you and review your blood tests in your first visit. We shall explain to you what needs to be done and how it is being done.


Venesection is performed in your second and subsequent visits, if clinically indicated.


Preparation for venesection


Continue taking your medication as usual, unless specified otherwise by your doctor.


Drink plenty of fluids the day before, especially in warm weather. Have at least 2 large glasses of water before the procedure.


Eat something salty in the 24 hours prior. Increasing your salt intake will help you restore your blood volume more rapidly after your venesection.


During procedure


Your blood pressure and other observations will be taken before and after the procedure is performed.


You will be lying down for the procedure.


You may feel a slight pinching when the needle is inserted (usually in your arm), but otherwise you should not feel any discomfort.


It generally takes approximately 15 minutes to drain 450 mls of blood.


After your procedure


You should drink fluids during this time and have something to eat within the next hour to ensure a quick recovery.


Avoid drinking alcohol for at least 8 hours.


Leave the bandage on for several hours.


Avoid strenuous exercise and heavy lifting for 24 hours.


What to expect


The procedure is safe and without side effects (in most cases).


Immediately after the procedure you may feel dizzy. This can be minimised by resting and drinking fluids.


You may feel a little lethargic for a couple of days.


You can resume all your normal activities after the procedure.


The frequency of the venesection treatments is different for everyone and is performed according to one’s condition. At first you may require up to weekly venesections. When your blood levels are under control you may only require the venesection at regular longer intervals.


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