In medicine (dermatology), there are several different types of cancer referred to under the general label of skin cancer. The the most common types are squamous cell carcinoma and basal cell carcinoma, while the most dangerous is malignant melanoma.

Skin cancer is an increasingly common condition, attributed in part to the degradation of the ozone layer and the consequently increased levels of ultraviolet radiation, and also due to the recent popularity of sun tanning (sun bathing), against which no level of sun screens offer any decisive protection.

Minor surface skin cancers are readily treatable by simple surgery, but if the cancer is allowed to grow then it will penetrate through the layers of skin and affect the lymphatic system. It may also metastasize and spread to other parts of the body.