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The Risks of Blood Transfusions

What You Need To Know About the Risks of Blood Transfusion


Updated May 06, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

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The Risks of Blood Transfusions

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The Risks of Blood Transfusions

Extensive screening helps prevent the transmission of infectious diseases, however, there are additional risks that one must consider when having a blood transfusion.

These risks must be weighed against the health concerns that can be caused by a lack of blood or blood cells, such as anemia and hypovolemia. In some cases a patient who is known to have a reaction to blood transfusions. This is because the risk of the reaction is lower than the risks associated with untreated bleeding.

Allergic (Hemolytic) Reaction To Blood Transfusion

An allergic reaction, also known as a hemolytic reaction, is a reaction to the administration of donor blood. Steps are taken to prevent severe reactions,starting with lab procedures that help prevent the administration of blood likely to cause a problem.

A hemolytic reaction occurs when the immune system of the patient receiving the blood transfusion destroys the transfused red blood cells. During the administration, additional procedures may be used to reduce the likelihood of a reaction to a transfusion, including giving blood slowly, so that any reaction can be noted prior to a substantial amount of blood being given, and closely monitoring for any signs of difficulty.

The severity of the reaction and the consequences of not giving the blood will determine if the blood will continue to be given or if the transfusion will be stopped. Benadryl, Tylenol or other pain medications, antihistamines or steroids may be given to stop or reduce a reaction to a transfusion.

Signs and Symptoms of an Allergic Reaction To Transfusion:


Fever: A sudden fever immediately after the transfusion of blood begins

Anxiety: A patient may have a feeling of impending doom or fear

Tachycardia: A faster than normal heart rate

Hypotension: Blood pressure is lower than normal

Pain: Chest pain and back pain

Dyspnea: Difficulty breathing

Kidney dysfunction: The kidneys can have difficulty filtering blood due to the dead blood cells attacked by the immune system

Bloody Urine: Along with kidney dysfunction, urine can show evidence of blood passed by the kidneys

Flank pain: Kidney dysfunction can be painful and presents as flank pain.

Increased Risk of Infection: If your blood donor was ill when they donated, or became ill shortly thereafter, your risk of infection is increased. Your risk is higher if your immune system is compromised or if you are extremely ill.

Death: Extremely rare, but possible, if hemolytic reaction is severe enough.

Diseases Spread By Blood Transfusion

The pool of donor blood is screened very carefully for infectious disease and is very safe. However, there is a very small chance of contracting life threatening diseases from donor blood. There is also a small chance of contracting other illnesses or infections from a blood transfusion.

The National Heart Lung and Blood Institute estimates that there is approximately a 1 in 2,000,000 chance of contracting Hepatitis C or HIV from a blood transfusion. There is a 1 in 205,000 chance of contracting Hepatitis B.

While it is essential that you are aware of the risks of transfusions, it is also important to keep these odds in perspective. For example, you are four times more likely to be killed by an asteroid than you are to contract HIV or Hepatitis C through a transfusion.

Illnesses That Can Spread By Blood Transfusion:

Transfusion Related Lung Injury (TRALI): In the hours following a transfusion, difficulty breathing, low blood pressure, fever are present, and a chest xray will show pulmonary infiltrates. The patient can have great difficulty getting enough oxygen in severe cases. This diagnosis is uncommon, but many believe it is under diagnosed and actually happens in one in every 300-5,000 transfusions, and is the third leading cause of transfusion caused death, depending upon the study.

Creutzfeldt-Jakob Disease (CJD): A very rare brain disease that is the human equivalent of mad cow disease. The risk of contracting CJD is extremely low, but it is possible, if a donor was infected with the disease.

Malaria: Typically transmitted by mosquito, the risk of contracting malaria is low in countries where malaria is uncommon. The risk is far greater in areas of the world, such as Africa, where malaria is frequently diagnosed. Malaria causes fever, shaking chills, anemia, muscle pain and headaches.

Cytomegalovirus (CMV): A virus that is very common, present in up to 80% of the population. Flu-like symptoms may be present when someone catches CMV, or may not be noticed. People with compromised immune systems may receive blood that has been screened for CMV.

Babesiosis and Lyme Disease: Spread by tick bites, both conditions cause chronic fatigue. Babesiosis is similar to malaria, presenting with fever, shaking chills and anemia. Lyme is most common near wooded areas where people hike, Babesiosis is most common near Long Island in the United States.

Chagas: A disease spread by parasites, Chagas is most common in Mexico, Central America and South America. Left untreated, it can cause organ damage, but medication is available through the Centers For Disease Control.

Syphillis: A very common illness spread by sexual contact, syphillis causes sores on the genitals and sometimes around the mouth. Syphillis is easily treated but can cause significant health problems if left to progress without medication.

Epstein Barr (EBV): One of the herpes viruses, EBV is believed to be present in the bodies of up to 95% of the population. When EBV is contracted by an adolescent, they risk of developing mono, or kissing disease, is an estimated 30-50%.

Herpes: While many illnesses are caused by the herpes family of viruses, most people mean genital herpes when they use the term. This virus causes lesions on the genitals and cold sores on the mouth.


Malaria and blood transfusion. Kitchen AD, Chiodini PL. National Blood Service, London, UK http://www.ncbi.nlm.nih.gov/pubmed/16430664

Red Blood Cell Transfusion and Nosocomial Infection Rates. Robert W. Taylor, MD, FCCM, Lisa Manganaro, RN, Jacklyn O'Brien, RN, Steven J. Trottier, MD, FCCM, Nadeem Parkar, MD, Christopher Veremakis, MD. Accessed August 2010.

The Risks of Dying. LiveScience. Accessed August 2010. http://www.livescience.com/environment/050106_odds_of_dying.html

Transfusion Reaction - Hemolytic. Medline Plus. Accessed August 2010. http://www.nlm.nih.gov/medlineplus/ency/article/001303.htm

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