Risk factors

Factors that may increase your risk of melanoma include:

• Fair skin. Having less pigment (melanin) in your skin means you have less protection from damaging UV radiation. If you have blond or red hair, light-colored eyes, and freckle or sunburn easily, you're more likely to develop melanoma than is someone with a darker complexion. But melanoma can develop in people with darker complexions, including Hispanic people and black people.
• A history of sunburn. One or more severe, blistering sunburns can increase your risk of melanoma.
• Excessive ultraviolet (UV) light exposure. Exposure to UV radiation, which comes from the sun and from tanning lights and beds, can increase the risk of skin cancer, including melanoma.
• Living closer to the equator or at a higher elevation. People living closer to the earth's equator, where the sun's rays are more direct, experience higher amounts of UV radiation than do those living farther north or south. In addition, if you live at a high elevation, you're exposed to more UV radiation.
• Having many moles or unusual moles. Having more than 50 ordinary moles on your body indicates an increased risk of melanoma. Also, having an unusual type of mole increases the risk of melanoma. Known medically as dysplastic nevi, these tend to be larger than normal moles and have irregular borders and a mixture of colors.
• A family history of melanoma. If a close relative — such as a parent, child or sibling — has had melanoma, you have a greater chance of developing a melanoma, too.
• Weakened immune system. People with weakened immune systems have an increased risk of melanoma and other skin cancers. Your immune system may be impaired if you take medicine to suppress the immune system, such as after an organ transplant, or if you have a disease that impairs the immune system, such as AIDS.