Transsexualism or gender dysphoria is the identification of a person with the opposite gender to their biological sex, and occurs in both men and women. Usually men who feel, think and act like women, or vice versa. As transsexuals are often in conflict with their sexual identity, some may get to request a change or gender reassignment. The sex change surgery, also known as sex reassignment surgery (SRS) is a surgical procedure performed in patients that have proven their transsexuality. This operation is a change in appearance of the external genitalia by reconstructive surgery and hormone treatments.