A good tan indicates good health. According to the American Osteopathic College of Dermatology, The American Cancer Society and the U.S. Department of Health and Human Services, tanning is the skin's way of telling you it has been damaged. Only one type of ultraviolet radiation is bad for you. Exposure to UV rays may damage the immune system. Sun exposure ages skin.
Skin acquires a leather-like appearance, becomes dry and tends to wrinkle prematurely.
UV radiation from the sun and a tanning bed is the same. Whether tanning is from natural sunlight or artificial light, the negative effects remain the same. Sunlight in small amounts can be beneficial. Sun can improve a person's emotional state and treat some skin disorders such as psoriasis. Too much sun can mean skin cancer.