Blood Transfusion: What to Expect (Singapore)

Written & reviewed by the BestDoctors.sg editorial team · Last updated 25 Aug 2026 · General information, not medical advice

Tell staff immediately if you feel unwell at any point during a transfusion — for example fever, chills, itching or a rash, breathlessness, chest or back pain, or just feeling anxious or “not right.” The transfusion can be paused and checked straight away. Tell the team beforehand about any previous transfusion reaction, allergies, or personal or religious beliefs about receiving blood.

What a transfusion is and why it is done

In a transfusion you receive blood or a blood component through a drip (IV line) into a vein. Most often you are given just the part you need: red cells, which carry oxygen, for significant anaemia or blood loss; platelets or plasma and clotting factors to help blood clot. Transfusions are used for major blood loss from surgery, serious injury or childbirth, for severe anaemia that cannot be corrected quickly another way, and for some cancers and blood disorders such as leukaemia and thalassaemia, or treatments that lower blood counts.

The checks that keep it safe

Before a transfusion, a blood sample is taken to find your blood group and to cross-match donor blood so it is compatible with yours — this is why a sample is usually needed first. Just before the blood is given, staff carefully check your identity, asking your name and date of birth and checking your ID band against the label on the blood unit, and you may be asked to confirm your details more than once. These grouping, compatibility and identity checks are the core safety steps that make a serious mismatch very unlikely.

What to expect during it

A cannula is placed in a vein, usually on the back of the hand or the forearm, and the blood bag is connected to it. The transfusion runs in over a period of time — commonly up to around four hours for a unit of red cells, sometimes longer, and you may receive more than one unit. Your temperature, pulse and blood pressure are checked before, during and after, especially in the first 15 minutes or so when a reaction is most likely to show. Most people feel no different, though the blood can feel a little cool going in; you can usually sit up, read or use your phone.

How safe it is

Blood in Singapore is voluntarily donated and rigorously screened and tested before use, and hospitals run strict identity and compatibility checks, so serious reactions are uncommon and staff actively watch for them. The risk of catching an infection from a transfusion is very low because donor blood is tested for a range of infections. Because reactions, while uncommon, are taken seriously, you are monitored closely throughout — the watching is a routine safeguard, not a sign that something is expected to go wrong.

Reactions to know about

Mild reactions can include a raised temperature, feeling hot or shivery, chills, itching or a skin rash; these are often managed simply by slowing or pausing the transfusion and are usually not serious. Rarer, more serious reactions include a significant allergic reaction, breathing difficulty, or a reaction to incompatible blood — these are uncommon and are the reason for close monitoring. Iron overload is a consideration only for people who need many repeated transfusions over a long time, and is managed by their specialist.

Telling staff if you feel unwell

The single most important thing you can do is speak up. Tell staff immediately if, at any point during the transfusion, you develop a fever, chills or shivering, itching or a rash, breathlessness, chest or back pain, or simply feel anxious or not right. The transfusion can be paused and you can be checked straight away. Severe breathing difficulty, swelling of the face, mouth or throat, or collapse is a medical emergency — in hospital, alert staff at once; in the community, call 995. After going home, tell a doctor if you develop a high temperature, unusual aches, yellowing of the skin or eyes, dark urine or back pain in the next day or two.

Your beliefs, consent and the Singapore picture

You will normally be told why a transfusion is recommended and asked to give consent, and you can ask questions freely. Where it is clinically appropriate, doctors also consider alternatives and blood-conservation approaches, known as patient blood management — such as treating iron deficiency or reducing blood loss during surgery. If you have religious or personal beliefs about receiving blood, tell your team; your wishes are handled respectfully, and the team can discuss alternatives with you rather than applying any pressure. In Singapore, blood is collected through the National Blood Programme, a partnership between the Health Sciences Authority and the Singapore Red Cross, and transfusions are given in hospitals. Donating blood, if you are eligible, helps sustain the very supply that this treatment depends on. The reassuring bottom line is that a transfusion is a routine, closely supervised treatment with strong safety checks built in — and that your part in keeping it safe is simply to tell staff at once if you feel unwell.

Related procedure & surgery topics

• Preparing for surgery
• Fasting before surgery
• General anaesthesia
• Sedation for procedures
• Day surgery
• Keyhole (laparoscopic) surgery
• Stitches & wound closure
• Wound care after surgery
• IV drip & cannula
• How to pay for surgery
• General surgeons in Singapore
• Sickle Cell Disease
• Haemochromatosis (Iron Overload)

Sources

• NHS — Blood transfusion: nhs.uk
• Health Sciences Authority — Blood donation: hsa.gov.sg
• Singapore Red Cross: redcross.sg