Skin cancer is the most common cancer, and occurs when skin cells grow out of control. There are two main types - non-melanoma skin cancers which are more common and rarely spread, and melanoma which is less common but more serious as it can spread. Ultraviolet (UV) radiation from the sun is the main cause of skin cancer. People at higher risk include those with fair skin or who have excessive sun exposure. Early detection is important - see a doctor if any new growths, spots or sores appear and don't heal. Screening is recommended annually after age 40. Protection methods include seeking shade, wearing sunscreen and protective clothing.