Gender dysphoria is a condition in which a person feels that there is a mismatch between their biological sex and their gender identity.
Biological sex is assigned at birth, depending on the appearance of the genitals. Gender identity is the gender that a person ‘identifies’ with or feels themselves to be.
While biological sex and gender identity are the same for most people, this is not the case for everyone. For example, some people may have the anatomy of a man but identify themselves as a woman, while others may not feel they are definitively either male or female.
Some people with gender dysphoria have a strong and persistent desire to live according to their gender identity, rather than their biological sex. These people are sometimes called trans-people. Some trans-people have treatment to make their physical appearance more consistent with their gender identity.
Gender dysphoria is not the same as transvestism or cross-dressing and is not related to sexual orientation. People with the condition may identify as straight, gay, lesbian, bisexual or asexual and this may or may not change with treatment.