Risk Factors for Melanoma


Understanding and being realistic about your risk factors for melanoma is an important step in prevention.

The most common risk factor for melanoma is exposure to UV light from the sun or indoor tanning beds or booths. Many skin melanomas are thought to occur as a result of sunburns or excessive exposure to UV light over time. It’s also possible for melanoma to develop in parts of your body not exposed to sunlight, such as the membranes lining your eyes, sinuses, anus, or vagina, though this is relatively rare.

In addition to UV light exposure, there are several other risk factors for melanoma.

  1. Age: The risk for melanoma increases with age; most melanomas occur in older people. Children are rarely affected.
  2. Atypical (dysplastic) moles: People with moles that are unusually large, irregularly shaped, poorly defined along the edges, multiple colors, or flat and bumpy are significantly more likely to develop melanoma. Sometimes these types of moles run in families.
  3. Many moles: Having more than 100 moles, even if they appear normal, is associated with an increased risk for developing melanoma.
  4. Large congenital moles: Although the risk varies depending on their size, having unusually large moles at birth is a possible precursor to melanoma.
  5. Personal or family history of melanoma: If you’ve already been diagnosed with melanoma, you’re at a significantly increased risk for developing it again. You’re also at a higher-than-average risk for melanoma if your parents or siblings have had it.
  6. A light complexion: Although people with any skin color can develop melanoma, having a fair complexion (light-colored eyes or hair, prominent freckles, easily sunburned, not able to tan) puts you at a significantly higher risk for the illness.