Scottsdale, Arizona - Skin cancer is the most common form of cancer, but many people ignore their risks. Dr. Cathy Newman, a Mayo Clinic dermatologist, offers a simple way to evaluate marks on your skin to see if they might be skin cancer.

"There are basal cell cancers," Dr. Newman says. "There are squamous cell cancers and melanoma. Melanoma is the most dangerous of the skin cancers."

Dr. Newman says more than 1 million Americans have melanoma right now or a history of it.

"Melanoma is more common in the sun-exposed areas, but ... it can be other places," she says. "So one of the big things that we push in Dermatology is trying to get people to look at all their skin – not just the sun-exposed areas."

And check regularly, because the earlier you catch a melanoma, the easier it is to treat.

Dr. Newman says to remember the A, B, C, D, Es of melanoma when you're checking.

"A" is for "asymmetry": One half is unlike the other half.

"B" is for "border irregularity": If a mole starts developing a tail or irregular borders.

"C" is for "color": If a mole changes color, doesn't match the color of other moles or varies color from one area to another.

"D" is for "diameter": If a mole starts getting bigger.

And "E" is for "evolving": Keep checking for any other changes in a mole.

But don't just check for it. Protect against it.

"We are very big advocates of patients using sun protection, and that includes shade, hats, sunscreen," Dr. Newman says.