A suntan or sunburn is a sign that skin has been damaged by ultraviolet (UV) rays.
Melanin is the pigment that gives skin its color. People with light skin have less melanin than people with dark skin. When skin is damaged by UV rays, the body makes more melanin to try to protect against further damage. This extra melanin gives suntanned skin its darker appearance.
But a suntan does not provide good protection against the harmful effects of UV rays. In fact, a suntan is a sign that skin has already been damaged, and tanned skin can continue to be damaged when exposed to UV rays.
For people with light skin, exposure to UV rays can lead to sunburn in as little as 10 to 15 minutes. The redness of a sunburn is caused by increased blood flow to skin that has been damaged.
Exposure to UV rays is the leading cause of skin cancers, including basal cell carcinoma and squamous cell carcinoma. These cancers often occur on skin that has been damaged by years of sun exposure, although they can occur on other areas of the body as well.
If you tan frequently or have a history of severe sunburns, you are also at an increased risk of melanoma, the most dangerous type of skin cancer.
Exposure to UV rays increases the risk of premature skin aging and may also increase the risk of eye problems such as cataracts, macular degeneration, and corneal damage.
Indoor tanning is not a safe alternative to sunbathing. Tanning beds, booths, and lamps produce a similar amount of UV radiation as the sun. Skin damage (a tan or a burn) from indoor tanning increases the risk of skin aging, skin cancer, and eye problems, just like damage from sunlight.
Apply broad-spectrum, water-resistant sunscreen with an SPF of 30 or higher before you go outside.
Use plenty of sunscreen—about 1 oz (2 tbsp) for your whole body.
Do not use sunscreen that is past its expiration date.
Reapply sunscreen after 2 hours in the sun and after swimming or sweating.
While outdoors, wear sunglasses and a hat with a wide brim (about 4 in) all the way around it.
Wear protective clothing (tightly woven long-sleeved shirts and long pants or skirts offer the most protection).
Limit your time in the sun and seek shade, especially between 10 am and 4 pm.
Do not use tanning beds.
Remember that skin damage from the sun can occur on cloudy days.
Pain from a sunburn is usually worst between 6 and 48 hours after sun exposure. A cool bath, cool compresses, and over-the-counter medicines like ibuprofen or acetaminophen can help. Drink water to stay hydrated. If your skin is not blistered, apply moisturizing cream or aloe vera gel to help with discomfort.
Extreme sunburn can lead to shock, dehydration, and other serious reactions. If you experience rapid heartbeat, rapid breathing, dizziness, fainting, nausea, chills, fever, or headache with a sunburn, call your doctor right away.
American Academy of Dermatologywww.aad.org/spot-skin-cancer/learn-about-skin-cancer/prevent-skin-cancer/how-to-select-a-sunscreen
US Food and Drug Administrationwww.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/Tanning/ucm116432.htm
US National Library of Medicinewww.nlm.nih.gov/medlineplus/ency/article/003227.htm
To find this and previous JAMA Patient Pages, go to the Patient Page link on JAMA’s website at jama.com. Many are available in English and Spanish.
Published Online: July 2, 2015. doi:10.1001/jama.2015.8045.
Sources: American Academy of Dermatology, Centers for Disease Control and Prevention, US Food and Drug Administration, US National Library of Medicine
Topic: Skin Care
Thompson AE. Suntan and Sunburn. JAMA. 2015;314(6):638. doi:10.1001/jama.2015.8045