Caption

Sickle cell anaemia. Here, normally rounded red blood cells have become curved, elongated sickle-shaped cells. Sickle cell anaemia is an inherited blood disease largely affecting black people, in which the red blood cells contain abnormal haemoglobin, the oxygen-carrying pigment. In areas of deoxygenated blood the haemoglobin distorts the red blood cells into a sickle shape, causing bone ache and organ damage. The fragile sickle cells are easily destroyed in the bloodstream. Magnification: x650 when printed at 10 centimetres wide.