Vitiligo (vit-ih-LIE-go) is a disease that causes the loss of skin color in blotches. The extent and rate of color loss from vitiligo is unpredictable. It can affect the skin on any part of your body. It may also affect hair and the inside of the mouth. Normally, the color of hair and skin is determined by melanin.The exact cause of vitiligo is unknown.It is believed to be due to genetic susceptibility that is triggered by an environmental factor such that an autoimmune disease occurs. This results in the destruction of skin pigment cells.Risk factors include a family history of the conditionor other autoimmune diseases, such as hyperthyroidism, alopecia areata, and pernicious anemia. It is not contagious.Vitiligo is classified into two main types: segmental and non-segmental.Most cases are non-segmental, meaning they affect both sides; and in these cases, the affected area of the skin typically expands with time.About 10% of cases are segmental, meaning they mostly involve one side of the body; and inthese cases, the affected area of the skin typically does not expand with time.Diagnosis can be confirmed by tissue biopsy.