The sun produces ultraviolet (UV) radiation, which reaches the earth even on a cloudy day. Tanning beds and sun lamps also produce UV light. Skin cells react to UV radiation by producing melanin, a pigment that causes the skin to darken. Melanin production itself is not harmful, but the change in skin colour is a telltale sign that your skin has been damaged by UV rays.
Your skin cells absorb UV radiation. The radiation attacks your DNA, which provides the instructions for your cells to live, grow and die at the appropriate time. With every sunburn or overexposure, tiny errors appear in the DNA. These errors are passed on to each new generation of skin cells, building up over time.
The body naturally works to repair the DNA damage. However, the more UV radiation you throw at your skin, the harder it is for your cells to repair damaged DNA.
Repeated DNA damage from sun exposure puts you at greater risk for skin cancer. Over time, the DNA can lose its ability to control new cell growth. Skin cancer happens when the skin cells start to multiply uncontrollably. Some types of skin cancer can be deadly.
The risk of developing skin cancer increases as your total exposure to UV radiation builds up over time. It doesn’t matter whether the UV exposure comes from the sun or through tanning beds – the bottom line is that it’s really harmful to your skin.