Most transfusions are completed without any problems. However, like any medical treatment, side effects can happen. Hospital staff are trained to recognize and treat them quickly.

Common mild reactions

Fever and chills

·       You may feel hot, cold or start shivering.

·       This is often due to your immune system reacting to donor white cells or proteins.

·       Staff will stop the transfusion temporarily, check you, and may give medicines like paracetamol before deciding whether it is safe to continue.

Mild allergic reactions (rash, itching)

·       You might develop hives (small itchy bumps) or general itching.

·       Nurses usually stop the transfusion briefly and give an antihistamine.

·       If symptoms settle and there are no other concerns, the doctor may restart the transfusion.

These mild reactions are uncomfortable but rarely dangerous.

More serious reactions (less common)

Breathing difficulty, chest pain, or wheezing

·       This can be due to fluid overload (too much volume too fast), an allergic reaction, or a rare lung reaction.

·       The transfusion is stopped immediately.

·       You may receive oxygen, diuretics (to remove extra fluid), or other emergency treatments.

Severe allergy (anaphylaxis)

·       Very rare but serious.

·       Symptoms include sudden difficulty breathing, swelling of face or throat, drop in blood pressure, and feeling of doom.

·       The team will stop the transfusion, call for emergency help and give injections (like adrenaline), oxygen and other life‑saving measures.

Acute hemolytic reaction (wrong blood type)

·       Very rare in modern practice due to strict checks.

·       Symptoms can include fever, back or chest pain, dark urine, and a sudden drop in blood pressure.

·       This is a medical emergency; transfusion is stopped at once, and treatment is started immediately.

Delayed reactions (hours to days later)

Some reactions may appear after you have left the hospital, such as:

·       Fever or jaundice (yellowing of eyes or skin) due to delayed destruction of transfused cells.

·       Rash or itching starting later.

·       Dark urine or feeling unusually unwell.

·       Symptoms of infection if, despite strict testing, a rare infection was transmitted.

If you notice any of these, contact your doctor or return to the hospital and clearly state that you recently had a blood transfusion.

How hospitals reduce risks

To keep reactions as rare as possible, hospitals and blood banks:

·       Use strict identity checks and labeling systems.

·       Screen every unit for major infections.

·       Cross‑match donor units with patient samples before transfusion.

·       Train staff to recognize and respond to reactions quickly.

For most patients, the benefits of a needed transfusion are far greater than the small risk of serious side effects, especially inside a properly run hospital.