Transgender people come from all walks of life - they are lawyers, doctors, nurses, dentists and builders - with many living ordinary and unremarkable lives without anyone realising their background.
Prof Kevan Wylie, consultant in sexual medicine at Sheffield’s Porterbrook Clinic, said changing attitudes mean that people are now far more willing than before to come forward to ask for help.
He said: “We have seen a change across society in the last 15 years. Society has become much more understanding of transgender issues.
“With the internet there is much more support and understanding available.”
The Porterbrook Clinic in Nether Edge - one of just eight specialist gender dysphoria clinics in the UK - has a broad role in offering advice on sexual and relationship issues.
Launched in 1974, the clinic at first had 12 patients a year who were offered advice but were treated elsewhere in the country.
The service - now run by Sheffield Health and Social Care Trust - significantly expanded in 1998 and since then has developed a range of advice, treatment and support services.
The clinic now sees about 50 new patients a year, and at any one time supports 160 people at different stages of their treatment.
People are referred for treatment by their GP and have a psychiatric assessment to ensure they have no underlying mental health issues.
The service offers an initial assessment programme, and as part of this service users will be offered psychological support to help decide if any additional support is needed before embarking on treatment to change to the opposite gender.
Prof Wylie said: “About a third of our patients choose to have more psychological support. They are making a life-changing decision and it is important to ensure they fully understand, for example, that once you start hormone treatment, changes in the body such as the loss of fertility are irreversible.”
Before they undergo surgery individuals are encouraged to live fully in the chosen gender role - with advice, support and hormonal treatment.