Patient Information on Blood Transfusion

Why might a transfusion be needed?

Blood is needed for the human body to work properly. The need for transfusion depends on the kind of condition a patient has. Most transfusions are given to treat anemia (a low blood count) or severe bleeding. The benefit of a transfusion is to improve the patient’s condition. When anemia or bleeding is extremely severe, a patient may die if a transfusion is not given.

How is blood transfused?

Blood is given into a vein (usually an arm vein) using a new sterile disposable needle. The transfusion may be of red blood cells, plasma, platelets or other specialized products made from blood. A doctor will decide on the right amount and type of blood product required for treatment.

Is it safe?

Blood transfusion is a common procedure with low risk. Blood is safer than it has ever been, but is not risk-free. Some problems that may occur with transfusion are listed below:

  • Bruising or swelling might occur where the needle is put into the vein
  • Minor and temporary reactions occur in about 1 in 100 people. These reactions include fever, chills or rash during or shortly after transfusion
  • All blood is tested for infectious diseases, but there is still a very small risk of disease transmission. The risk of getting HIV is 1 in 7.8 million, Hepatitis B is 1 in 153,000 and Hepatitis C is 1 in 2.3 million. The risk of getting other viruses (known or unknown) is very small.
  • Other rare but serious risks include acute lung injury at 1 in 5,000, anaphylaxis is 1 in 40,000 and errors resulting in the wrong blood being transfused is 1 in 40,000
  • These risks are small compared to the potential benefits of transfusion. For comparison the chance of dying in a motor vehicle accident is 1 in 10,000 and the chance of death by drowning is 1 in 100,000.

What are the alternatives to transfusion?

Alternatives include patients storing their own blood before surgery, drugs to increase the red blood cells count, and a parent or guardian donating blood for their child. Not all patients can use these alternatives and when bleeding or severe anemia is life-threatening, there is no effective substitute for blood transfusion.

If you are interested in alternatives to transfusion of adults please refer to the information available on the Blood Conservation Clinic here at Credit Valley Hospital.

If you have questions or concerns regarding potential transfusion of blood, please contact your doctor.

If you would like to speak to the Hospital’s Transfusion Safety Technologist, she can be reached at (905) 813-1100 ext 5038 or


A Patient’s Perspective on Transfusion Medicine online e-learning educational tool (available in English and French)


Credit Valley Hospital Patient Information on Transfusion pamphlet [157kb pdf]