Even more than premature aging, the most alarming consequence of sun exposure is skin cancer—the most common form of cancer. Dr. Oz says there are actually three types of skin cancer.
Basal cell cancer, which starts at the base of the skin, is the most common form. Typically caused by sun damage, it starts with a scaly area that, if it advances, will eventually gain a pearly appearance. Squamous cell tumors get a scaly appearance early. As they advance, the skin puckers in.
The third type of skin cancer is melanoma, which Dr. Oz calls "the big one." Melanoma comes from melanin, the cells that make pigment, so there are a few indicators.
To identify melanoma, doctors use the "A, B, C, D" method: