Therapeutic venesection

A therapeutic venesection is a procedure that reduces the levels of blood within your body. This is sometimes required if a person has too many red blood cells, which can slow down blood-flow and increase the risk of developing blood clots, among other things.

A common example of a condition that may require therapeutic venesection treatment is haemochromatosis, an inherited condition associated with ‘iron overload’. Over time, this can lead to complications such as arthritis, liver damage and heart problems, so managing the condition is important. Certain lung and heart problems can sometimes require this treatment too.

As well as reducing blood levels by around 1 pint, if required, a therapeutic venesection can also reduce blood thickness to safe levels.

The procedure is very similar to what happens when you donate blood. You’ll be asked to lie on a comfortable chair, and a specialist nurse will insert a needle into a vein in your arm. A flexible tube, connected to a bag, will be attached – the blood will slowly drain into this. Only a small amount is removed and the process is usually completed in around 10-15 minutes. Apart from a slight scratch when the needle is inserted (and the area may feel a bit bruised for a few days afterwards), the process is completely painless. However, some people do feel a bit dizzy or lightheaded – drinking plenty of fluid can help and the nurse will check on you throughout.

Once the required amount has been removed, the needle will be carefully removed and a pressure dressing applied. You should be able to go home shortly afterwards.

How frequently the treatment is required can vary from person to person. Your consultant will be able to help monitor and advise on this.

Payment options


Why wait? At Hadley Wood Hospital, we offer a quick and easy way to get immediate access to the healthcare you need. We welcome both self-paying patients and those covered by private health insurance.

Find out more

Specialist consultants


You’ll be looked after by leading consultants offering the highest level of expertise in their field. No matter what your healthcare concern, our Consultants will be able to advise the best course of treatment.

Search specialists

Treatments and services


We offer everything from health screening checks to diagnostic tests and minor surgery. We’re here to help you make the right choices for your health, so that you can focus solely on your recovery.

View treatments