26-year-old finally diagnosed after five years of tests
Fitness fanatic Kathryn Weir's life turned into a 'living hell' when her weight mysteriously shot up, making her so fat she was ashamed to leave the house.
The sporty 26-year-old, who enjoyed 90-minute sessions in the gym, ballooned from a trim size 10 to a size 18 in the space of a few weeks.
Doctors were baffled when Kathryn Weir, from Widnes, Cheshire, suddenly began to gain weight around her stomach for no apparent reason.
Her face became bloated and swollen and she began to grow dark hairs on her chest and back.
Size matters: Kathryn was healthy before the shock weight gain that 'snapped' her leg bone
Her bones became so brittle that one of her legs 'snapped' when she was on a night out - breaking under her weight.
She was finally diagnosed with Cushing's syndrome, a rare tumour on the pituitary gland, after five years of anguish.
The condition, which affects fewer than one in 200,000 people, causes a small tumour to develop next to the pituitary gland,affecting the hormones released into the bloodstream.
Kathryn, who works as a carer for people with disabilities, said: 'Cushing's syndrome has transformed me into a completely different person.
'I'm ashamed to go anywhere or see anyone now. I rarely leave the house.
'I used to take such pride in my appearance - I was devastated when I started gaining weight. My friends tried to save my feelings and didn't say anything, but when we went out, people assumed I was pregnant, because my belly was so huge, but my arms and legs are still very skinny.
'I was mortified when I kept having to tell people I wasn't expecting.
'I couldn't find any clothes to fit me, because my middle was so big but my legs weren't.
'If I don't tie my trousers up with a belt, they fall down because my legs are so much smaller than my bum.
'I wasn't eating any more than normal, and I wasn't exercising any less - but everyone was baffled by my symptoms.
'I couldn't understand what was happening to me - and neither could my doctors.'
Cushing's syndrome also causes 'moon face' symptoms
After five years of tests and hospital visits, Kathryn was diagnosed by doctors at Warrington Hospital in December 2010.
The syndrome affects the amount of Cortisol released into the body, causing major rapid weight gain around the middle.It also makes sufferers' faces bloated and round - known as a 'moon face'.
The tumour can also cause brittle bones or osteoporosis, a condition usually associated with elderly women.
Kathryn is due to have an operation next month in which surgeons are hoping they will be able to remove the tumour and get her life back to normal.
She added: 'I'm really very lucky that I was able to be diagnosed and that surgeons are hopeful that they can cure me.
'It took years for doctors to realise what was wrong with me, but some people never get diagnosed.
'If the tumour had never been spotted, the osteoporosis could have got so bad that it could have killed me.
'I've been in a living hell for the last six years - and it's only now that I can start to see a light at the end of the tunnel.
'There are times when I've felt like I didn't even want to go to work, because I felt everyone was staring at me.
'But thanks to my family and friends, who have stood by me, I have managed to make it through, and hope that I can go back to being fit and healthy Kathryn soon.'