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Risk Factors

A risk factor is anything that increases your chance of developing a disease, including cancer. For example, smoking is a risk factor for heart disease and lung cancer. Risk factors may have to do with your personal traits or habits, or they may be due to your family history of a disease or condition or to your exposure to the environment.


By knowing your risk factors, you can take steps to reduce your chances of developing melanoma or increase your chances of finding the disease in its early, more treatable stages.


Major Risk Factors for Melanoma

1. Moles

Your moles or other skin lesions are a major risk factor for melanoma. Moles are colored spots on the skin usually shades of brown ranging from flesh colored to dark brown. The medical term for a mole is melanocytic nevus (plural nevi).

For more on moles click here.


2. Skin Type

Skin type is the primary risk factor for developing melanoma. Fair-skinned races are at much greater risk than those with darker skins. This is because darker skinned people produce more melanin, the pigment that gives color to skin and hair, and protects the skin from damage from ultraviolet radiation.


Caucasians are 20 times more likely to develop melanoma than African Americans. It is important however to note that while Caucasians are increased risk, melanoma affects people of all races.


For more on skin types and risk click here.


For more on melanoma in people of color click here.

3. UV Exposure

Frequent and intense exposure to UV radiation, either from the sun or from artificial indoor tanning beds is the major environmental risk factor for melanoma. It has been shown that repetitive and severe sunburns (sunburns that result in blistering) especially in childhood, put one at risk for melanoma. People who have fair skin that burns or freckles easily need to be especially careful in the sun. Intermittent exposure to intense sunlight is more strongly associated with the development of melanoma than continuous daily sun exposure.

For more on UV exposure click here.


For more on tanning beds click here.


For more on tanning beds and legislation to limit their usage click here.


4. Personal/Family History

The risk of developing melanoma is significantly increased if there is a family history of melanoma in one or more of your first degree relatives (parent, brother or sister, or child). About 10% of all people with melanoma have a family history of melanoma.

For more on the genetics of melanoma click here.

Top 17 Risk Factors for Melanoma


Risk Factor Risk Level
Mole, new or preexisting that has changed
High (10-400x greater)
Atypical moles (dysplastic nevi) with family history and a previous melanoma
Very high (500x greater)
Atypical moles (dysplastic nevi) with family history but without previous melanoma
High (148x greater)
Atypical moles (dysplastic nevi ) without  family history and without previous melanoma
Moderately high (7-27x greater)
Congenital nevus Moderately high (2-21x greater)
Caucasian Moderately high (20x greater)
Lentigo maligna Moderately high (10x greater)

20 moles at least 2mm diameter (if 50 nevi or more)

Moderately high (7-54x greater)
5 moles at least 5mm diameter (if 12 nevi or more) Moderately high (10-41x greater)
5-8 nevi at least 7mm diameter (if 50 nevi or more) Moderately high (6-17x greater)
Prior melanoma in the skin Moderately high (9x greater)
Melanoma in an immediate family member Moderately high (nearly 10x greater)
Immunosuppressed Moderate (4x greater)
Sun-induced freckles by history Moderate (3x greater)
Sun sensitivity, relative inability to tan Moderate (3x greater)
Red or blond hair, green or blue eyes 2x greater
Sun/UV exposure Depends on skin type and other risk factors




Information in the chart above was provided by A. Rhodes, as modified from Rhodes et al, in 5th edition of Fitzpatrick's Dermatology in General Medicine, p. 1026 Table 90-1.


  • The vast majority of moles are harmless and do not become a concern over someone's lifetime.

  • However, a change in the size, shape, or color of an existing mole or the appearance of a new mole is often the first sign of melanoma and should be evaluated.

  • In addition to changes in appearance, moles that begin to itch, burn, or bleed are also suspicious for a possible transformation to melanoma.


4 major risk factors for melanoma:

  • Moles

  • UV Radiation

  • Family History

  • Race