Suntans are cause by long time exposure to the rays of the sun light. Suntan occurs when the skin cells produce too much melanin in the melanocyte and they can happen in little as just under a minute of sun exposure. Suntans do fade themselves and sometime they don't and then in that case they would have to be treated and they can be treated in many means. Suntans can last between a day to lifetime. How to get rid of suntan Using skin lightening creams. Doing a laser treatment. Doing a chemical peel treatment.