Gener identity disorder (GID) is the formal diagnosis used by psychologists and physicians to describe a person who has been assigned one gender, usually on the basis of their sex at birth (compare intersex disorders), but identifies as belonging to another gender, and feels significant discomfort or the inability to deal with this condition. It is a psychiatric classification and describes the problems related to transsexuality, transgender identity and more rarely transvestism. It is the diagnostic classification most commonly applied to transsexuals.