About 4.5 million people in the United States and Canada receive blood transfusions each year. A blood transfusion is a process used to put healthy blood—most importantly, red blood cells—into your body. Most people who receive multiple transfusions have a blood condition that causes anemia. Anemia can happen if the body doesn't make enough red blood cells or if the ones it makes aren't healthy. Transfusions replace the missing or unhealthy red blood cells with healthy ones.
Transfusions may be used to treat certain diseases of the blood, such as:
- Sickle cell disease
- Thalassemia
- Myelodysplastic syndrome
- Other types of anemia
Find out more about transfusions
With every transfusion, you also get extra iron. Iron won't go away on its own. The body has no way of removing the extra iron. This buildup of iron may lead to iron overload. A simple blood test called a serum ferritin test can tell you how much iron is in your body. If your iron level continues to be over 1000 mcg/L (micrograms per liter), you have iron overload.

