What causes skin cancer?

Ultraviolet (UV) radiation from sunlight is the main cause of skin cancer -- the most common type of cancer in the United States. About one in five Americans develops skin cancer during his or her lifetime.

The main cause of skin cancer is being exposed to ultraviolet (UV) rays from the sun. Warm summer weather often means taking part in more outdoor activities. While it’s important to take opportunities to be more active, when it comes to being out in the sun, people should be sure to take care of their skin.

Trinity Health is a Catholic health care organization that acts in accordance with the Catholic tradition and does not condone or support all practices covered in this site. In case of emergency call 911. This site is educational and not a substitute for professional medical advice, always seek the advice of a qualified health care provider.

Skin cancer develops in the cells in your skin. Normally, these cells go through a growth cycle in which old cells die and are pushed out by new cells continuously. In skin cancer, the DNA that controls that growth cycle is damaged, most commonly by ultraviolet radiation from the sun. This causes an overgrowth of cells, which eventually builds up and forms a tumor. The type of skin cancer you have depends on the type of cell that is affected, but all types of skin cancer begin in the epidermis (the topmost layer of skin).

Dr. Chrysalyne D. Schmults, MD
Dermatologist (Skin Specialist)

Skin cancer is caused by changes in certain types of cells in the skin. Watch Chrysalyne Schmults, MD, Dermatologist at Brigham and Women's Hospital discuss how these cells develop into basal cell carcinoma, squamous cell carcinoma or melanoma.

Continue Learning about Skin Cancer Causes & Risk Factors

Am I more at risk for skin cancer than my grandparents were?
Dr. Mehmet Oz, MDDr. Mehmet Oz, MD
The sunlight our skin absorbs is harsher than it was in the past. As the ozone layer has depleted, t...
More Answers
Why is skin cancer more common in old age?
UCLA HealthUCLA Health
Skin cancer is more common with age because damage from ultraviolet (UV) light builds up over ti...
More Answers
Does sun exposure increase my risk for skin cancer?
Kelly TraverKelly Traver
Avoid excess sun. Skin cancer is directly related to sun exposure. Ultraviolet radiation damages th...
More Answers
What Increases My Risk for Skin Cancer?
What Increases My Risk for Skin Cancer?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.