Although the causes are not totally understood, melanoma, like all cancers, is not contagious. There are certain risk factors, but having any of these risk factors does not mean that you will get melanoma, just like not having any of the risk factors does not protect you from the disease.
According to the National Cancer Institute, some of the risk factors include:
Family history of melanoma – About 10 percent of all patients with melanoma have family members (two or more close relatives) who also have had this disease.
Dysplastic nevi – The risk of melanoma is greater for people with a large number of dysplastic nevi, especially for people who have a family history of both dysplastic nevi and melanoma.
History of melanoma – People who have been treated for melanoma are at a higher risk of developing a second melanoma.
Weakened immune system – People with weak immune systems due to cancer, immune suppressing drugs, or AIDS are at a higher risk for developing melanoma.
Many ordinary moles (more than 50) – Since melanoma begins in melanocytes, having many moles increases risk of this disease.
Ultraviolet (UV) radiation – Much of the worldwide increase in melanoma is related to an increase in the amount of time people spend in the sun. The disease is also more common in people who live in areas that get larger amounts of UV radiation from sun, such as Texas in the United States, or Australia in the world. UV radiation can lead to premature aging of the skin and skin damage that can lead to melanoma. Sunlamps and tanning booths also cause skin damage, probably increasing the risk of melanoma.
Severe, blistering sunburns – People who have had one or more severe, blistering sunburns as a child or teenager are at increase risk for melanoma. Sunburns in adulthood are also a risk factor for melanoma.
Fair skin – People who have fair skin that burns or freckles easily and who have red or blond hair and blue eyes are at higher risk for melanoma.