A transfusion reaction results when your body's
immune system attacks the blood you received in a
blood transfusion or when the transfused blood causes
an
allergic reaction.
The most serious transfusion reactions occur when your ABO or Rh
blood type and that of the transfused blood do not
match. These reactions result in the destruction of the transfused blood and
can be life-threatening. Less commonly, a mismatch of one of the more than 100
minor blood types can cause a serious reaction.
Mild transfusion reactions usually are caused by a mismatch of the
minor blood types between your blood and the transfused blood. A mild reaction
may involve fever, shortness of breath, pain, rapid heart rate, chills, and low
blood pressure. While a mild transfusion reaction is frightening, it is rarely
life-threatening when treated quickly.
Allergic reactions to blood can cause itching,
hives, and wheezing. A severe allergic reaction can
result in
anaphylactic shock, a life-threatening
condition.