The sunlight that reaches the earth has ultraviolet A and B (UVA and UVB) rays. These ultraviolet (UV) rays are the main causes of damage to the skin from the sun. Some people are more susceptible than others to skin damage. Certain factors may mean that you have an increased risk of developing skin cancer:

• A personal history of skin cancer
• A family member with skin cancer
• More than 50 moles
• Abnormal moles (atypical moles), or moles larger than 6 mm (0.2 in.), about the size of a pencil eraser
• A weakened immune system
• Severe sunburns—even one—as a child, or sunburns as an adult
• Living in a sunny or high-altitude climate or near the equator
• Fair skin that burns or freckles easily and does not tan

Sunburns in childhood are the most damaging to the skin. The earlier in life that you are burned by the sun, the greater the risk of developing skin cancer later in life.

Some people believe that tanning protects against a sunburn. But the amount of sun exposure needed to get a tan can by itself cause excessive skin damage and outweigh any possible benefit.

Continue to Why?

You can stop skin cancer before it starts.

• Exposure to the sun is the most common cause of skin cancer. Sunburns do the most damage, but sustained time in the sun increases the risk of skin damage and mole growth.
• Most early skin cancers are easily seen on the skin and may be curable if treated early.
• Some people have a higher risk of developing skin cancer. If you are aware that you have a higher risk, have regular skin examinations and take steps to protect your skin.

Continue to How?

Avoiding skin cancer can be as simple as protecting your skin and taking a good look at it regularly. While sunscreen plays a vital role in protecting your skin from UV radiation, it can't prevent skin damage if you are exposed to the sun's rays for long periods of time. Experts recommend that you use multiple methods to fully protect your skin.

Protect your skin

• Stay out of the sun during the peak hours of UV radiation, from 11 a.m. to 4 p.m.
• Wear protective clothing:
  • Wide-brimmed hats that protect the face and neck
  • Tightly-woven clothing made of thick material, such as unbleached cotton, polyester, wool, or silk
  • Dark clothing with dyes added that help absorb UV radiation
  • Loose-fitting long-sleeved clothing that covers as much of the skin as possible
  • Clothing that has sun protection factor (SPF) in the fabric that does not wash out
• Wear sunscreen with an SPF of 15 or higher, summer and winter, on both cloudy and clear days:
  • SPF of 11 offers minimal protection.
  • SPF of 12 to 29 offers moderate protection.
  • SPF of 30 and above offers high protection.
• Apply sunscreen that blocks both UVA and UVB radiation to all exposed skin, including lips, ears, back of the hands, and neck. Apply sunscreen 30 minutes before going in the sun, and reapply it every 2 hours and after swimming, exercising, or sweating.
• Wear wraparound sunglasses that block at least 99% of UVA and UVB radiation.
• Be careful when you are on sand, snow, or water, because these surfaces can reflect 85% of the sun's rays.
• Avoid artificial sources of UVA radiation, including sun lamps and tanning booths. Like the sun, they can cause skin damage and increase the risk of skin cancer.

A child's skin is more sensitive to the sun than an adult's skin and is more easily burned. Babies younger than 6 months should always be completely shielded from the sun. Children 6 months and older should have their skin protected from too much sun exposure.

Know the ABCDEs of early detection

Skin cancer can be cured if found and treated early. If it is not discovered or treated until too late, it can spread throughout the body and may be fatal. Skin cancer often appears on the trunk of men and on the legs of women. Learn your ABCDEs, the changes in a mole or skin growth that are warning signs of melanoma:

• Asymmetry: One half doesn't match the other half.
• Border irregularity: The edges are ragged, notched, or blurred.
• Colour: The pigmentation is not uniform. Shades of tan, brown, and black are present. Dashes of red, white, and blue add to the mottled appearance. Colour may spread from the edge of a mole into the surrounding skin.
• Diameter: The size of the mole is greater than 6 mm (0.2 in.), or about the size of a pencil eraser.
• Evolution: There is a change in the size, shape, symptoms (such as itching or tenderness), surface (especially bleeding), or colour of a mole.

Get to know your skin

Skin cancer, including melanoma, is curable if spotted early. A careful skin examination may identify suspicious growths that may be cancer or growths that may develop into skin cancer (precancers).

• Examine your skin once every month. Get to know your moles and birthmarks, and look for any abnormal skin growth and any change in the colour, shape, size, or appearance of a skin growth.
• Check for any area of skin that does not heal after an injury.
• Have your doctor check your skin during any other health examinations. Most experts recommend having your skin examined regularly.
• Bring any suspicious skin growths or changes in a mole to the attention of your doctor.

Continue to Where?

Now that you know how to protect your skin from UV radiation and skin cancer, it's a good time to do a thorough skin self-examination. Then you will be ready to talk with your doctor at your next visit about your skin's health, particularly if you notice any suspicious growths.