The first descriptions of the pathological desire to change your gender date back to the middle of the last century. This pathology was designated by N. Ellis as a perverse sensation of ones sex, a sexual-aesthetic inversion. The term "transsexualism" was proposed by N. Benjamin, who was the first to describe this phenomenon from a scientific point of view. Transsexualism - TS (eonism, sexual-aesthetic inversion, mental hermaphroditism) is a pathological state of a person, consisting in a polar divergence of the biological and civil sex, on the one hand, with the mental sex, on the other. In other words, Tc is a violation of sexual self-identification, which consists in the mismatch of the feeling of one's gender identity with the nature of the external genital organs. TS - persistent awareness of belonging to the opposite sex. The diagnosis of TS is made by adults and adolescents who have reached puberty, who wish to change their genitals and live as a representative of the other sex, after the exclusion of mental disorders. A person with TS feels like a man enclosed in a womans body, and vice versa. In a harmoniously organized body of a certain gender (the chromosomal, gonadal and morphological sex correspond to each other, providing the possibility of fertilization, and in women and childbearing) there lives an another gender soul. And this soul not only lives, it feels, thinks, suffers, experiences desires and drives that it cannot realize. In fact, we are talking about chronic stress, therefore, in most patients with TS, suicidal behavior can be detected. TS is a rather rare pathology. There is no data on vehicle prevalence in our country. When studying the prevalence of TS in other countries, it was noted that TS is found in many, if not all, ethnic groups, despite significant cultural differences, which can serve as indirect evidence of the biological basis of this pathology. The average age of patients with TS who go to the doctor about sex change is 20-24 years (51% of patients). This is typical for both female and male vehicles. At the age of 15-19 years, this percentage is 12, at the age of 25-29 years - 25, at the age of 30-34 years - 11, over 35 years old - no more than 1. According to the majority of authors, male TS significantly prevails over female - the ratio 3: 1.