Sun tanning causes a big problem for our skin. It may cause skin diseases and skin cancer too. Sun tanning caused due to dangerous Ultraviolet rays of sun, these UV rays attack on our skin and damage the beauty of our skin. There is a layer of melanin under the skin, when these UV rays attack on skin, the melanin pigmentation absorb all the UV rays and make that part of skin shady. It protects our body up to an extent.