How does skin cancer begin?

Sun damage: With rare exception, most skin cancers are caused by sun damage. Any new skin bump which is new, enlarging, and changing is concerning. The older you are, and the more sun exposure you have had, the higher the risk of skin cancer. Melanomas risk is remembered as abcd: asymmetry, irregular borders, irregular coloration, diameter >6mm. If in doubt, have it check out by your doctor.

Ultraviolet light: Uv light (from the sun or tanning booths) is responsible for inducing the most common forms of skin cancer (basal cell carcinoma and squamous cell carcinoma), and probably most melanomas. However there are other causes, since skin cancer can occur in non-sun-exposed areas as well. By applying a good sunscreen lotion daily and staying away from tanning booths, you can prevent most skin cancers.

Skin cancer : Clinically, a small skin cancer starts as a small non healing patch or growth. Others start as as a changing or new mole that is typically but not always asymmetrical, irregular bordered , different colors, size larger than a pencil head eraser or that itches bleeds. See a dermatologist for a skin exam yearly or whenever a suspicious area develops.