What causes skin cancer? Page Content"Sun exposure is the main cause," says Jungho Kwon, M.D., a board-certified dermatologist at Kelsey-Seybold Clinic. "The sun’s ultraviolet rays come in two types: UVA and UVB. Over time, these solar rays can damage the DNA in your skin and may lead to several types of skin cancer, including malignant melanoma – the deadliest form."Dr. Kwon says that outdoor UV rays are not the only threat."The frequent use of indoor tanning beds, which can deliver a concentrated flow of UV rays even stronger than the sun’s, also increases the risk of skin cancer."She says skin cancer is an equal-opportunity disease."It can develop in all ethnic groups. However, people with fair skin, light-colored eyes, blonde or red hair, and those with a tendency to freckle are more prone to skin cancer"Dr. Kwon adds that having a family history of skin cancer may also increase your risk."Texas summers are harsh. Sun protection practices can significantly reduce your chances of developing skin cancer," she adds. "Stay out of the sun between 10 a.m. and 4 p.m. when rays are strongest; apply a broad-spectrum sunscreen that protects against both UVA and UVB rays with a sun protection factor (SPF) of 30 or higher; and wear protective clothing, such as a wide-brimmed hat and sunglasses."Dr. Kwon cares for patients at Kelsey-Seybold’s Clear Lake Clinic in Webster, and at the Main Campus near the Texas Medical Center.