Sickle-cell disease (sickle-cell anaemia) affects the red blood cells, which carry oxygen around your body. In people with this condition, the red blood cells become 'sickle' shaped when they are not carrying oxygen. These sickle cells tend to get stuck in small blood vessels, causing pain in the chest and joints. Sickle-cell disease sufferers often become anaemic, and may also be affected by gallstones, eye problems and strokes. There is no cure for this condition, although the symptoms can be treated.