What are transfusion reactions?

If you’ve experienced severe blood loss or low blood levels, a blood transfusion can help restore the blood you’ve lost. It’s a routine procedure that adds donated blood to your own. Blood transfusions can be lifesaving. However, it’s important that the blood is accurately matched to your blood type. If the blood type is not a match, you can experience a transfusion reaction. These reactions are rare, but they can be harmful to your kidneys and lungs. In some cases they can be life threatening.

Your doctor may recommend a blood transfusion if you’ve lost blood or are not producing enough blood. This can be due to:

  • illness
  • surgery
  • cancer
  • infection
  • burns
  • injury
  • other medical conditions

Blood transfusions are most commonly done for blood components, such as red blood cells, platelets, or plasma. Before a blood transfusion, a medical provider will draw your blood. This sample will be sent to a laboratory for typing and crossmatching. Typing is when the lab determines blood type. Crossmatching is testing to determine if your blood is compatible with a donor’s blood of the same type.

A number of blood types exist, including:

  • A positive
  • A negative
  • O positive
  • O negative
  • B positive
  • B negative
  • AB positive
  • AB negative

Knowing your blood type is important because red blood cells contain antigens, or protein markers, corresponding to these blood types. If a laboratory gives you the wrong type of blood, your immune system will detect any foreign proteins on the red blood cells of the wrong blood type and attempt to destroy them.

Blood banks have thorough testing processes to make sure blood is safe and correctly typed for use. A doctor or nurse will explain any risks of blood transfusions to you and will closely monitor you while you’re receiving the blood.

Most blood transfusion reactions occur while you’re receiving blood or immediately after. A doctor or nurse will stay with you while you receive the transfusion. They will check your vital signs and watch for symptoms that you may be having a reaction.

Transfusion reaction symptoms include:

In some instances, however, transfusion reactions take place days after the transfusion. Pay close attention to your body after a transfusion, and contact a doctor if you feel something isn’t right.

Antibodies in the recipient’s blood can attack the donor blood if the two are not compatible. If the recipient’s immune system attacks the red blood cells of the donor, it is called a hemolytic reaction.

You can have an allergic reaction to a blood transfusion as well. These symptoms can include hives and itching. This reaction type is often treated with antihistamines.

Another transfusion reaction type is the transfusion related acute lung injury (TRALI). This reaction may occur when donor plasma contains antibodies that cause damage to the immune cells in the lungs. This lung damage results in fluid buildup in the lungs and can severely limit the ability of the lungs to supply oxygen to the body. This reaction usually occurs within six hours of receiving blood.

In rare instances, bacteria may be present in the donated blood. Giving this contaminated blood to a recipient can lead to infection, shock, and death.

A transfusion reaction can also occur if a person receives too much blood. This is known as transfusion-associated circulatory overload (TACO). Having too much blood can overload your heart, forcing it to work harder to pump blood through your body and resulting in fluid buildup in the lungs.

You also can experience iron overload due to too much iron from donor blood. This can damage your heart and liver over many transfusions.

Transfusion reactions are not always serious. However, some can be life threatening. Serious complications include:

Blood banks make every effort to screen and test blood. A sample of recipient blood is often mixed with potential donor blood to ensure compatibility.

Before the blood is given to you, the blood label and your identity will be thoroughly checked. This ensures the doctor or nurse is giving the proper blood products to the right recipient.

If you or your medical provider observes blood transfusion reaction symptoms, the transfusion should be immediately stopped. A laboratory representative should come and draw blood from you and take the donated blood for testing to ensure they were matched appropriately.

Transfusion reactions can vary in severity. Some symptoms can be mild and treated with acetaminophen to reduce any pain or fever.

Your doctor may also prescribe intravenous fluids or medications to reduce the likelihood of kidney failure and shock.



Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.