If tanned skin is left untreated, it can result in serious issues such as sunburn and premature ageing in the long run. This could speed up the appearance of wrinkles, fine lines and crows feet as the sun rays also break down collagen in the skin. This may also result in the formation of freckles and sun spots. In extremely severe cases, tanning can also lead to cancer of the cells called melanoma that begins in the cells that produce melanin in the deep layers of the skin.