What to Expect During a Blood Transfusion

A blood transfusion during cancer treatment replaces blood cells your body cannot make enough of right now, most often because treatment has affected your bone marrow. Your team should explain which blood count led to the recommendation, how long the transfusion takes, and which symptoms to report right away.

This page is educational. It is not medical advice and does not suggest a test or treatment.

Transfusions are routine in oncology. Chemotherapy and radiation can affect the bone marrow, where blood cells are made. That can lead to low red blood cells, called anemia, low platelets, or both. A transfusion is not a sign that treatment failed. It is a standard way to support your body while the marrow recovers. Still, a first transfusion is not routine to the person receiving it. It is fair to want to know exactly what will happen.

Anemia means you have fewer red blood cells than normal. It can cause tiredness, shortness of breath, lightheadedness, a fast heartbeat, or pale skin. Low platelets raise your risk of bruising or bleeding. Both are common, expected effects of many cancer treatments, not a separate illness layered on top of your cancer. A simple blood test tracks both counts, so your team usually sees a transfusion coming before you feel it.

A blood transfusion is a safe, common procedure. You receive blood through a thin tube called an IV line. It goes into a vein, or into a port if you already have one for treatment. The blood usually comes from volunteer donors. It is carefully matched to your blood type and tested beforehand. Getting the blood usually takes one to four hours. The exact time depends on how much you need. Staff check your vital signs before starting, and again at intervals throughout. Many people read, rest, or have a visitor during the infusion.

Ask which blood count or symptom led to the recommendation, so you understand why this transfusion, now. Ask roughly how long the visit will take, so you can plan your day and arrange a ride if needed. Ask what monitoring happens during and after, and whether you will need repeat blood counts afterward to see how well it worked.

Tell staff right away, during the transfusion, about fever, chills, rash, itching, chest tightness, back pain, shortness of breath, bloody urine, dizziness, fainting, or any sudden feeling of being unwell. These can be early signs of a transfusion reaction. In a serious reaction, your immune system attacks the donated blood cells. Symptoms most often show up during the transfusion or right after it ends. Most reactions, when caught early, respond well. Staff stop the transfusion right away and start treatment. That is exactly why they want to hear about a new symptom the moment it starts, not after the visit ends.

If you develop symptoms, the team stops the transfusion immediately and checks your vital signs. They send blood samples to confirm what happened and treat the reaction directly, which might mean medicine for a fever or allergic symptoms, or fluids to support your kidneys. Most reactions resolve without lasting harm when they are caught and treated early. That is the entire reason for the close monitoring during your visit, not a sign that something is expected to go wrong.

• How does my transfusion fit with my diagnosis, my treatment, and my current symptoms?
• After my transfusion, what should I do now, what can wait, and what should make me call sooner?
• Is there a written plan, handout, or referral that would make this easier to follow?
• Who do I contact after hours about my transfusion, and what should I have ready?

Reactions can also start after you leave, sometimes several days later.

• Call 911 or go to an emergency department if breathing becomes hard, your chest feels tight, or you faint after getting home.
• Call 911 or go to an emergency department if you develop a fever with hard chills, pain in your back or side, or urine that looks dark, red or bloody after a transfusion. Together these can mean the donated red cells are breaking down, which needs treating at once. Say you were transfused and give the date.
• Call your care team the same day if you get a fever on its own, or an itchy rash that keeps spreading. If you are also having chemotherapy, a fever is a medical emergency: call them straight away, whatever the hour, and go to an emergency department if you cannot reach them.
• Call your care team within a day or two if the tiredness or breathlessness that led to the transfusion has not eased at all, or your skin or eyes look yellow.

Transfusion questions connect to anemia, platelet counts, fatigue, bleeding risk, and how transfusions fit around your treatment schedule. Related pages: What to Expect at a Chemo Teaching Visit, What to Expect When Biopsy Results Come by Phone.

• MedlinePlus (National Library of Medicine, NIH) — Blood Transfusions.
• MedlinePlus (National Library of Medicine, NIH) — Hemolytic Transfusion Reaction.
• National Cancer Institute — Anemia and Cancer Treatment.