Sickle-cell disease is one of the most common severe monogenic disorders in the world. Haemoglobinpolymerisation leading to erythrocyte rigidity and vaso-occlusion is central to the pathophysiology of this disease although the importance of chronic anaemia, haemolysis and vasculopathy has been established. It is an inherited genetic condition by the production of abnormal hemoglobin which leads to the deformation of red blood cells into a rigid crescent shaped form these sickle shaped cells are less flexible and obstructing blood flow and ischemia and long term organ damage.The disease predominantly affects individuals of African , middle eastern. It is a condition where the bone marrow fails to produce adequate amount of blood cells including red blood cells , white blood cells, platelets. This can be caused by autoimmune destruction exposure to toxic substances, viral infections. Aplastic anemia leads to pancytopenia . Aplastic anemia can affect individual of any age and characterized by a rapid onset and potentially life threatening complications without prompt treatment. Aplastic anemia is an historic disease. The first patient was described bythe young Paul Ehrlich in 1885 its clinical features were described by Cabot and other pathologists in the early 20th century.