Types of Blood
It is important to transfer the right type of blood during a blood transfusion. Otherwise, serious complications might happen when the body rejects the new blood. There are basically 4 blood types: A, B, O, and AB. Each type can be negative or positive. People with O blood are universal donors because this type is compatible with all other types. When a person is bleeding heavily and in a critical condition, a doctor might need to use blood from a universal blood donor. In these cases, a test can be done to determine the right blood type for a blood transfusion. [3]
