The life cycle of red blood cells (RBC) is normally 110 to 120 days after which they are naturally broken down. The process of RBC breakdown is termed haemolysis. The broken down RBCs are usually removed from the blood system by the spleen. The bone marrow continuously makes red blood cells to replenish the lost ones.
But some conditions like infections, autoimmune disorders, genetic disorders, certain medications, toxins, use of haemodialysis and heart-lung bypass machine, etc. may cause the RBCs to break down too soon. Failure of the bone marrow to replenish the lost RBCs with equal numbers leads to low red blood cell count. In conditions like sickle-cell disease an increased rate of RBC destruction can cause haemolytic crisis leading to anaemia, jaundice, and increase in immature red blood cells (reticulocytosis). Mother’s antibodies crossing the placenta to the unborn child in the womb can cause haemolytic disease of the new-born.