NHS Plymouth makes special consideration to patients who demonstrate that they are "significantly different to the general population of patients with the condition in question".
Emma also thought her genital area was abnormal. She said before her surgery her labia was "very long, dark, stretchy. It looked disgusting - shrivelled up".
"It was the only thing in my life that made me feel depressed. I was very excited about having labiaplasty. I thought it was going to be the end of all my problems. I thought it was going to look lovely, like a little designer vagina."
Though it is now smaller, Emma is still unhappy with her labia's appearance.
Women seeking labiaplasty need more opportunity to discuss their concerns, said Dr Lih-Mei Liao, a consultant clinical psychologist at University College London Hospitals.
"Worries about the labia are quintessentially psychological. When a woman says she is worried about her labia, surgeons may hear the word 'labia' and operate, I hear the word 'worry'.
"It's difficult when surgery is being advertised as a straight forward solution. It makes it hard for these women to engage psychologically with what's going on."
She added that psychologists "simply aren't being accessed as surgery is being presented as the obvious solution".
The British Association of Aesthetic Plastic Surgeons is calling for mandatory psychological screening before cosmetic surgery. It said a recent report found that routine psychological checks were carried out in less than 35% of clinics.
Dr Liao believes that a woman's anxiety or dissatisfaction with certain areas of her life may manifest itself as body image concerns.
"Surgery may have its place, but it needs to be seen as an extreme solution," she added.