Patients with acquired hemolytic anemia often require blood transfusions, especially if their condition is quite severe. It is sometimes impossible, though, to find compatible blood, as the autoantibody in the patient's blood serum can react poorly with normal red blood cells from a donor. Special compatibility tests need to be conducted before authorizing a blood transfusion for patients with this condition to ascertain what the optimal unit of red blood cells would be. When a transfusion is approved, a donor will give healthy blood through an intravenous line (IV). The blood is then preserved, matched with an appropriate recipient, and transfused through an IV into the patient's blood vessels. The receiving treatment can take anywhere from one to four hours, depending on the severity of the condition and how much blood the patient needs.