The skin is made up of building blocks known as cells. When the skin is exposed to UV radiation, skin damage to these cells occurs and they can become cancerous. However, the body’s DNA normally repairs this skin damage.
But when the body has been overexposed to UV radiation there can be too much skin damage to the cells for the DNA to repair. This is the normal result of sunburn. Sunburn leads to permanently damaged cells that when re-exposed to UV radiation will become even more damaged. This can then develop into skin cancer.
The most critical years for sun protection are during childhood. Sunburn and overexposure to UV radiation during these years greatly increase the chance of skin cancer. Long-term exposure over many years will also increase the chances of skin cancer.