American Melanoma Institute · 5 min read
The main melanoma risk factors in rough order of strength, how age and sex shape the numbers, and which risks a person can change.
The American Cancer Society estimates that about 112,000 new melanomas will be diagnosed in the United States in 2026. Anyone can develop melanoma, including people with dark skin and people who rarely see the sun. Still, risk is far from evenly spread. A few traits and exposures account for most of the difference between people, and they differ a great deal in strength.
The order below is approximate. Studies measure these factors in different ways, and many people carry several at once.
Mole count is one of the best predictors doctors have. Most adults have 10 to 40 common moles. People with more than 50 have a clearly higher risk, and risk keeps rising with the count. Most moles never turn into melanoma. A high count signals skin whose pigment cells are prone to growing, and most melanomas in these people arise on normal-looking skin, not inside a mole.
Atypical moles (dysplastic nevi) add to that. These moles are larger than a pencil eraser, with uneven color or a smudged border. Having 5 or more is a recognized risk marker. People with many atypical moles plus melanoma in close relatives, a pattern called familial atypical multiple mole melanoma (FAMMM) syndrome, have a very high lifetime risk and are usually followed with regular exams and photographs.
A personal history counts heavily. According to the American Academy of Dermatology (AAD), melanoma survivors have about 8 times the usual risk of developing another, separate melanoma. Follow-up skin exams after treatment look for new melanomas as well as recurrence. Past basal cell or squamous cell skin cancer raises melanoma risk too, since it shows the skin has absorbed substantial UV damage.
About 1 in 10 people with melanoma has a family history of it. Having a parent, sibling, or child with melanoma raises risk to more than 2 times the average. Part of that comes from inherited genes such as CDKN2A, and part from shared skin type and sun habits.
Skin type is inherited too, and it matters a great deal. Melanoma risk is much higher in people with fair skin that burns or freckles easily, red or blond hair, and blue or green eyes. The lifetime risk of melanoma is about 3% (1 in 33) for White Americans, about 0.5% (1 in 200) for Hispanic Americans, and about 0.1% (1 in 1,000) for Black Americans.
Lower risk still leaves some risk. In people with darker skin, melanoma is often found at a later stage, in part because neither patients nor clinicians expect it. It also tends to appear in places that get little sun, such as the palms, the soles, and under the nails.
Ultraviolet (UV) radiation is the main cause of melanoma that a person can control. The pattern of exposure matters. Melanoma is tied most closely to intense, intermittent sun, the kind that causes blistering burns on skin that is usually covered. The AAD reports that 5 or more blistering sunburns between ages 15 and 20 raise melanoma risk by 80%.
Tanning beds deliver concentrated UV. Using them before age 20 raises melanoma risk by 47%, and risk climbs with each session. Women under 30 who tan indoors are 6 times more likely to develop melanoma than those who don't.
Immune cells find and remove damaged pigment cells. When the immune system is suppressed, that surveillance weakens. Organ transplant recipients have about 2 times the usual melanoma risk, and their melanomas are more likely to spread. Risk is also higher in people with certain blood cancers, such as chronic lymphocytic leukemia, and in people with poorly controlled HIV.
Xeroderma pigmentosum is a very rare inherited condition in which cells can't repair UV damage. Affected children develop skin cancers, including melanoma, on sun-exposed skin at a young age.
Melanoma risk rises with age. The median age at diagnosis is 67, and almost 8 in 10 new cases are found in people 55 or older, according to National Cancer Institute SEER data.
The pattern by sex flips in midlife. Before age 50, women have higher rates than men. After 50, men have higher rates, and the gap widens with each decade. Across all ages, men are diagnosed at a rate of about 28 per 100,000 each year compared with about 18 per 100,000 for women.
Men also die of melanoma more often. Of roughly 8,510 melanoma deaths expected in 2026, about 5,500 will be in men. Melanomas on the back and scalp, common sites in men, are hard to notice without a partner or a mirror. Researchers are still studying how much of the gap comes from behavior and how much from biology.
Most of the list is fixed: mole count, skin and hair color, family history, age, and sex. None of these can be altered, but each can be acted on. People with fixed risk factors benefit most from learning what their own moles look like, checking their skin monthly, and asking a doctor whether regular professional skin exams make sense for them.
A person can control 3 factors, and all involve UV:
UV protection started in adulthood still helps. In an Australian randomized trial of 1,621 adults, those assigned to daily sunscreen for about 4 years developed half as many melanomas over the following decade as those who used sunscreen at their own discretion.
