Blood Transfusion: What to Know If You Get One

Medically Reviewed by Sabrina Felson, MD on November 01, 2021
5 min read

A blood transfusion is a way of adding blood to your body after an illness or injury. If your body is missing one or more of the components that make up healthy blood, a transfusion can help supply what your body is missing.

Depending on how much blood you need, a transfusion can take between 1 and 4 hours. About 5 million Americans need a blood transfusion every year, and the procedure is usually safe.

Your blood is made up of several different parts including red and white cells, plasma, and platelets. “Whole blood” refers to blood that has all of them. In some cases, you may need to have a transfusion that uses whole blood, but it’s more likely that you’ll need a specific component.

There are many reasons you might need to receive a blood transfusion. These are just a few of them:

When you get a transfusion, the blood you’re given has to work with the type of blood you have (either A, B, AB, or O). Otherwise, antibodies in your own blood will attack it, and cause problems. That’s why blood banks screen for blood type, Rh-factor (positive or negative), as well as anything that can cause infection.

About 40% of people have type O blood, which is safe to give almost anyone in a transfusion. If you have type O blood, you’re called a universal donor.

If you have type AB blood, you can receive any type of blood and you’re called a universal recipient. If you have Rh-negative blood, you can only receive Rh-negative blood.

There are several common kinds of blood cell transfusions:

  • A red blood cell transfusion may be used if you have anemia or an iron deficiency.
  • Platelets are tiny cells in the blood that help you stop bleeding. A platelet transfusion is used if your body doesn’t have enough of them, possibly because of cancer or cancer treatments.
  • A plasma transfusion helps replace the proteins in your blood that help it clot. It may be needed after severe bleeding or if you have liver disease.

You’ll likely go to your doctor’s office or a hospital to receive your blood transfusion. The new blood will be given to you through a needle and an IV line. You’ll be monitored in case there are any problems.

In general, blood transfusions are considered safe, but there are risks. Sometimes complications show up immediately, others take some time.

Fever: It’s usually not considered serious if you get a fever 1 to 6 hours after your transfusion. But if you also feel nauseated or have chest pain, it could be something more serious. See your doctor right away.

Allergic reactions: It’s possible to experience an allergic reaction to the blood you receive, even if it’s the correct blood type. If this happens, you’ll likely feel itchy and develop hives. If you have an allergic reaction, it’s likely to happen during the transfusion or very shortly after.

Acute immune hemolytic reaction: This complication is rare, but is a medical emergency. It happens if your body attacks the red blood cells in the blood you’ve received. This normally takes place during or right after your transfusion, and you’ll experience symptoms like fever, chills, nausea, or pain in your chest or lower back. Your urine might also come out dark.

Delayed hemolytic reaction: This is similar to an acute immune hemolytic reaction, but it happens more gradually.

Anaphylactic reaction: This happens within minutes of starting a transfusion and may be life-threatening. You may experience swelling of the face and throat, shortness of breath, and low blood pressure.

Transfusion-related acute lung injury (TRALI): This is a rare, but potentially fatal reaction. It shows up within hours of the start of the transfusion in the form of a fever and low blood pressure. TRALI damages your lungs. It may be caused by antibodies or other substances in the new blood. Even though it’s rare, it’s still the leading cause of transfusion-related death in the United States.

Bloodborne Infections: Blood banks thoroughly screen donors and test donated blood for viruses, bacteria, and parasites, but infections are still a rare possibility.

  • HIV: Your chance of contracting HIV through donated blood is 1 in 2 million (a lower risk than being struck by lightning).
  • Hepatitis B and C: Your chance of contracting hepatitis B is about 1 in 300,000 and your risk of contracting hepatitis C is about 1 in 1.5 million.
  • West Nile virus: Your chance of contracting West Nile virus is about 1 in 350,000.
  • Zika virus: In 2016, the FDA began recommending that blood centers screen for Zika. Most people who have it don’t show any symptoms.

Hemochromatosis (iron overload): You can get too much iron in your blood if you have multiple blood transfusions. This can damage your heart and liver.

Graft-versus-host disease: This complication is extremely rare, but is usually fatal. It happens when the white blood cells in the new blood attack your bone marrow. You may be more likely to experience this complication if you have a weakened immune system.