What Are the Risks of a Blood Transfusion?

Most blood transfusions go very smoothly. However, mild problems and, very rarely, serious problems can occur.

Allergic Reaction

Some people have allergic reactions to the blood given during transfusions. This can happen even when the blood given is the right blood type.

Allergic reactions can be mild or severe. Symptoms can include:

• Anxiety
• Chest and/or back pain
• Trouble breathing
• Fever, chills, flushing, and clammy skin
• A high pulse or low blood pressure
• Nausea (feeling sick to the stomach)

A transfusion is stopped at the first signs of an allergic reaction. The health care team determines how mild or severe the reaction is, what treatments are needed, and if the transfusion can safely be restarted.

Viruses and Infectious Diseases

Some infectious agents, such as HIV, can survive in blood and infect the person receiving the blood transfusion. To keep blood safe, blood banks carefully screen donated blood.

There is a risk of catching a virus from a blood transfusion, but it's very low.

• HIV. Your risk of getting HIV from a blood transfusion is lower than your risk of getting killed by lightning. Only about 1 in 2 million donations may carry HIV and transmit HIV if given to a patient.
• Hepatitis B and C. The risk of having a donation that carries hepatitis B is about 1 in 205,000. The risk for hepatitis C is 1 in 2 million. If you receive blood during a transfusion that contains hepatitis, you will likely develop the virus.
• Variant Creutzfeldt-Jakob disease (vCJD). Variant CJD is the human version of Mad Cow Disease. It's a very rare, yet fatal brain disorder. There is a possible risk of getting vCJD from a blood transfusion, although the risk is very low. Because of this, people who may have been exposed to vCJD aren't eligible blood donors. Go to the AABB Web site for more information about vCJD.

Fever

You may get a sudden fever during or within a day of your blood transfusion. This is usually your body's normal response to white blood cells in the donated blood. Over-the-counter fever medicine will usually treat the fever.

Some blood banks remove white blood cells from whole blood or different parts of the blood. This makes it less likely that you will have a reaction after the transfusion.

Iron Overload

Getting many blood transfusions can cause too much iron to build up in your blood (iron overload). People with a blood disorder like thalassemia, which requires multiple transfusions, are at risk of iron overload. Iron overload can damage your liver, heart, and other parts of your body.

If you have iron overload, you may need iron chelation therapy. For this therapy, medicine is given through an injection or as a pill to remove the extra iron from your body.

Lung Injury

Although it's unlikely, blood transfusions can damage your lungs, making it difficult to breathe. This usually occurs within about 6 hours of the procedure. Most patients recover. However, 5 to 25 percent of patients who develop lung injuries die from the injury. These people usually were very ill before the transfusion.

Doctors aren't completely sure why blood transfusions damage the lungs. Antibodies (proteins)—which are more likely to be found in the plasma of women who have been pregnant—may disrupt the normal way that lung cells work. Because of this risk, hospitals are starting to use men and women's plasma differently.

Acute Immune Hemolytic Reaction

Acute immune hemolytic reaction is very serious, but also very rare. It occurs if the blood type you get during a transfusion doesn't match or work with your blood type. Your body attacks the new red blood cells, which then produce substances that harm your kidneys.

The symptoms include chills, fever, nausea, pain in the chest or back, and dark urine. The doctor will stop the transfusion at the first sign of this reaction.

Delayed Hemolytic Reaction

This is a much slower version of acute immune hemolytic reaction. Your body destroys red blood cells so slowly that the problem can go unnoticed until your red blood cell level is very low.

Both the acute and delayed hemolytic reactions are most common in patients who have had a previous transfusion.

Graft-Versus-Host Disease

Graft-versus-host disease (GVHD) is when white blood cells in the new blood attack your tissues. GVHD is usually fatal. People who have weakened immune systems are the most likely to get GVHD.

Symptoms start within a month of the blood transfusion. They include fever, rash, and diarrhea. To protect against GVHD, patients with weakened immune systems should receive blood that has been treated so the white blood cells can't cause GVHD.