A blood transfusion can help if you've lost a lot of blood, or if you have certain health conditions that affect your blood or bone marrow.
You may need a blood transfusion if you do not have enough healthy red blood cells. This is called anaemia and it can be caused by:
You may also need a blood transfusion if you have a condition which means your blood does not clot as well as it should. This can mean you bleed a lot, or for longer than usual.
Depending on your condition, you can be given a transfusion containing:
Sometimes other treatments will be tried before you have a blood transfusion. The doctor will tell you about any alternatives.
Blood transfusions take place in hospital.
A doctor or nurse will talk to you about what's going to happen and answer any questions.
You'll have a blood sample taken before starting the blood transfusion, to check the donor blood is the right blood group for you.
You'll usually be asked to sign a consent form. But if a blood transfusion is needed in an emergency, for example during surgery, it might not be possible to get your consent.
During a blood transfusion:
Your pulse, temperature and blood pressure will be checked before, during and after a blood transfusion.
A blood transfusion usually takes up to 4 hours, but it can take longer depending on how much blood you need.
You can usually go home after a blood transfusion unless you are very unwell.
Many people will start feeling better within 24 hours of getting a blood transfusion.
Before you leave hospital, the healthcare team will give you information about possible side effects and complications to look out for.
Many people have no side effects from having a blood transfusion.
You might have mild symptoms such as:
Slowing down or stopping the transfusion usually helps these symptoms.
It's rare, but it's possible to have a serious allergic reaction to a blood transfusion.
Tell your healthcare team immediately if you have any trouble breathing. They will know how to treat a serious allergic reaction.
A blood transfusion is a common and safe procedure.
Complications are rare but can include:
Complications can happen a few hours, days or even weeks after having a blood transfusion.
You have had a blood transfusion and:
Tell them you recently had a blood transfusion.
You can call 111 or get help from 111 online.
Tell them you recently had a blood transfusion.
Do not drive yourself to A&E.
The person you speak to at 999 will give you advice about what to do.
If you've had a blood transfusion since 1980, you can no longer be a blood donor. This is a precaution against variant Creutzfeldt-Jakob disease (vCJD).