when do person need repeated blood transfusion??
People need repeated blood transfusions in many diseased conditions such as when suffering from sickle cell anaemia, Thalassemia, blood cancer, etc. In most of these conditions, abnormal conditions occur in blood cells. So, to survive the patients have to obtainn healthy blood from the donors.
For example in Sickle cell anaemia, an abnormal type of haemoglobin called haemoglobin S is formed. Hemoglobin S changes the shape of red blood cells to sickle-like or crescents.It is a disease caused by a mutation in the amino acid at 6th position in the beta chain of hemoglobin which results in replacement of glutamine by valine. The major characteristics of this disease are anemia (less functional RBCs) and a tendency of the red blood cells to to deliver oxygen become less