Skin cancer often begins quietly with tiny mutations inside skin cells. Ultraviolet light, chemicals, or repeated irritation slowly damage DNA, but early changes are small and invisible. The skin keeps repairing itself, and the immune system removes many abnormal cells, allowing mutations to build unnoticed. Over time, some damaged cells begin dividing faster than normal. A patch of skin may thicken, a mole may darken, or edges may turn uneven, changes that are often ignored. When mutations reac