NHS websites say patients feel a mismatch between their biological sex and their gender identity. It is a recognised condition, not a mental illness, but patients nevertheless have to be assessed by two mental health professionals before they start treatment.
Anne, 44, from Perth, has had her first appointment after waiting almost a year to see a specialist in Glasgow.
She says: "The person I lived as for most of my life was all an act. The real person was within but I had to suppress that because I was ashamed."
She has found trying to live as Anne while waiting for treatment stressful. As a bus driver she has had to endure comments from passengers.
She says: "I have got to wear such thick make-up to hide the beard shadow it is a joke sometimes. I am signed off work now because of depression."
Anne hopes the new guidelines issued to health boards will ensure there are no unnecessary delays to a sex-change operation. She says: "It will mean everything because then my body will match my brain."