Skin cancer is caused by DNA damage, which can result from excess exposure to ultraviolet (UV) light. Having a previous  occurrence of skin cancer or a close family member with the disease also puts you at risk for skin cancer.  Other risk factors include having:

 a weak immune system

 unusual moles or a large number of moles

 white or light (fair)-colored skin, especially with freckles

 blond or red hair or blue or green eyes

 scars or burns on the skin, or skin diseases that make someone sensitive to the sun.