Blood transfusion complications and reactions: signs to look out for

A blood transfusion is a procedure in which blood from a donor goes into a vein in your arm through a narrow tube. The NHS says it may be needed if you have lost a lot of blood, from an accident, surgery or childbirth, or if you have a condition affecting the red blood cells or bone marrow, such as sickle cell disease or thalassaemia, or you are having treatment such as chemotherapy or radiotherapy. It may also be used if your blood does not clot as well as it should.

Depending on the condition, you may be given red cells for anaemia, platelets or plasma to help blood clot. A blood sample is taken beforehand to check the donor blood matches your blood group, and your pulse, temperature and blood pressure are checked before, during and after. A transfusion usually takes up to 4 hours but can take longer, and many people feel better within 24 hours.

The NHS says many people have no side effects. Some have mild symptoms, such as a high temperature, or feeling hot, cold or shivery, for which paracetamol may be given, or a skin rash for which an antihistamine may be given. Slowing down or stopping the transfusion usually helps these symptoms.

Staff monitor you during the transfusion precisely so that such reactions are noticed early. If you feel unwell in any way during a transfusion, say so straight away rather than waiting.

The NHS says it is rare, but possible, to have a serious allergic reaction to a blood transfusion, and asks you to tell the healthcare team immediately if you have any trouble breathing. They will know how to treat it.

Other complications listed by the NHS are infection, which is very unlikely because donor blood is tested for a range of infections before it is given, and having too much iron in your blood, which is a small possibility if you have many transfusions over time.

Because reactions can be delayed, the symptom lists in the next section are worth keeping to hand for several weeks after a transfusion.

The Kingston and Richmond NHS Foundation Trust leaflet lists signs of a reaction to tell staff about: a high temperature above 38 degrees, feeling feverish, hot and clammy, shivering, breathing problems, extreme tiredness, blood in the urine, passing much less or very dark urine, an itchy skin rash, feeling sick or vomiting, and lower back pain. It says reactions usually appear within 24 hours but can happen days or weeks later.

The NHS says to ask for an urgent GP appointment or contact NHS 111 if you have a high temperature or feel hot, cold or shivery, aching muscles for no reason, feel or are sick, have blood in your pee, are peeing very little or your pee is very dark, are bleeding from your mouth, bottom, nose or eyelids, have yellowing of the whites of the eyes or skin, or have lower back pain.

• Urgent GP appointment or NHS 111: high temperature, feeling hot, cold or shivery, unexplained aching muscles, being sick, blood in pee or very dark or little pee, bleeding from mouth, bottom, nose or eyelids, yellow eyes or skin, lower back pain.

• 999: severe difficulty breathing, a tingling or swelling mouth or throat, chest pain.

• Tell whoever you speak to that you recently had a blood transfusion.

The NHS says to call 999 if after a transfusion you have severe difficulty breathing, your mouth or throat is tingling or swelling, or you have chest pain, and to say you recently had a blood transfusion. It adds that you should not drive yourself to A&E; the person at 999 will advise what to do.

The Kingston leaflet similarly says to ring 999 if you feel extremely unwell, for example if you have difficulty breathing.

You can usually go home after a transfusion unless you are very unwell, and the team should give you information on possible side effects and complications to look out for before you leave. Keep the contact details for the ward or transfusion team handy for the first few weeks.

The NHS says that if you have had a blood transfusion since 1980 you can no longer be a blood donor; this is a precaution against variant Creutzfeldt-Jakob disease. The Kingston leaflet describes this as a national guideline.

Blood transfusions in the UK are given in hospital, in NHS and private hospitals alike, and the NHS page points patients to NHS Blood and Transplant for information leaflets. The checks, monitoring and reaction advice described above apply regardless of setting. Consent is normally sought beforehand, although the NHS notes that in an emergency such as surgery, consent may not be possible to obtain.

If you have concerns about whether you need a transfusion, the NHS says that sometimes other treatments will be tried first and the doctor will tell you about any alternatives; it is reasonable to ask about them.