Ryan McKenna always felt like a girl trapped inside a boy's body, but unlike many who suffer from gender identity disorders, Ryan didn't need surgery to become the female he believed he truly was.

As a child Ryan's mum Julie found small lumps on his chest, before a doctor said Ryan probably had high oestrogen levels, but would likely grow out of it over time.

At school, Ryan preferred hanging out with girls, and described himself as 'dress mad'.

Ryan is affected by a hormonal imbalance which can affect growth, fertility and behaviour.

The imbalance can pose serious psychological problems for those affected, but with support from loved ones, these issues can be overcome.

The first noticeable changes came in adolescence when Ryan began developing breasts and curvy hips at the same time as his female friends.

"My transformation was amazing. I was a little ginger boy, then I went curvy like a woman," Ryan told The Sun.

"I'm really lucky. I never got any facial hair and I haven't got an Adam's apple. My bum is perky like a woman's and my waist is narrow and hour-glassy," she added.

Ryan admits at times her childhood was difficult, especially when it came to not fitting in as a girl or a boy.

"At school I was always one of the girls. We'd talk about stuff like our boobs growing and giggle about boys. Sometimes they'd talk about their periods and forgot I don't get them. They’'re the only girls' thing I'm glad I haven't got."

But over the past year Ryan, who still lives at home with her family, has fully embraced his femininity, and says her family is to thank for the smooth transition.

"This year I grew into a woman and have never been happier," she told the Sun. "My dad is a real man's man, so he found it a bit difficult at first. But he's absolutely fine with it now."

Ryan has now begun to date men, who she makes aware of her situation, but hasn't yet fallen in love.