Sarah Haselgrove is just 16, but she has already undergone a shocking seventeen heart operations.
The teenager is the longest living youngster in Britain with so many complex cardiac problems.
But despite spending more than half her life in hospital, she is just a year behind at school and will sit her GCSEs next year.
The schoolgirl from Kent, was not expected to live a week and underwent five heart operations in her first year of life.
She was in and out of hospital throughout primary school and has faced three major surgeries in the last six years.
But Sarah has battled on to live a normal life, and even competes at carriage racing at Windsor Castle every year.
She said: 'There are lots of things I can't do, so I just concentrate on things I'm good at.
'I've had a lot of time spent in hospital beds, but I'm fine now, as long as don't overdo things.'
Sarah, who lives with her mother Nicky, 45, father Steve, 51, a nuclear power engineer, sister Holly, 13 and brother Stuart, 18, was born five weeks prematurely with a catalogue of problems including Hypoplastic Left Heart Syndrome.
Children with the rare condition do not often survive beyond infancy and only a few have survived into their teens.
Less than half of Sarah's heart was working properly and just hours after birth, weighing just 4lbs 4oz, she was rushed to The Royal Brompton Hospital in London for her first operation.
At just three days old, Sarah had surgery for coarctation of the aorta, where the main artery is narrowed and repaired using part of an artery from the left arm.
Mother Nicky, an ex legal secretary, said: 'She was so small the tubes and machines completely swamped her.
'We were told it was unlikely she'd survive but somehow Sarah battled through.'
But at just three months old, she was rushed back into hospital again for her second emergency surgery to close a hole in her atrium.
Nicky said: 'Sarah's heart had other holes, and was like a piece of Swiss cheese.
'She was so weak her little body would not cope without major work. There was little hope she would survive but we had to try.'
Amazingly Sarah pulled through the operation, but her first year of life was a constant battle and she underwent three more surgeries, to fit a cardiac catheter, repair her mitral valve, and carry out work on her right diaphragm.
The following year, she faced five more operations, including three sets of heart and lung echoes, surgery to replace her faulty mitral valve, and to drain excess pericardial fluid.
Doctors also fought to save her life after her diaphragm became paralysed and she was unable to breathe. Sarah was also constantly vomiting and had to be fed via a nasal gastric tube.
Sarah kept battling on but at the age of six, after she'd already spent most of her life in hospital, she faced her eleventh heart operation, another cardiac catheter.
Six months later, she had her twelfth and most complicated procedure to date, to remove an obstruction on her aortic valve and close holes between the ventricles.
Nicky said: 'It seemed never ending. She'd also endured stomach operations and treatment for numerous chest infections, pneumonia and bronchitis.
'I used to look at clothes for little girls and think, will she ever live to wear those?'
But despite her family's fears, Sarah, who remembers the operation, never doubted herself.
'I got a little nervous before each operation but I always knew I would come out the other side,' she said.
'It never really worried me. I suppose it's like a gut instinct.'
Finally Sarah was allowed home to her family but was still not strong enough to attend school, and between the ages of eight and nine she faced two more surgeries.
The thirteenth involved fitting a new cardiac catheter and her fourteenth involved a cardio echo which confirmed she had an irregular heart rhythm.
A month later she was admitted to Great Ormond Street Hospital for her fifteenth procedure, to have a pacemaker fitted.
Nicky said: 'It is a dangerous operation for a child as young as Sarah was.
'She was very badly bruised after this surgery and looked so frail.'
In September that year Sarah underwent her sixteenth surgery, to replace her mechanical mitral valve with an upside down aortic valve, which was larger and would continue working as she grew.
She recovered well, despite doctors' concerns numerous scar tissue would restrict their access to her heart.
Sarah was finally well enough to go to mainstream school, where she did brilliantly to catch up on four years of work.
She started a normal life with her friends, meeting up after school and going shopping at weekends, although she was not allowed to do any sports.
It was not until she was 13 that Sarah needed her final and seventeeth surgery to replace her existing pacemaker with a larger biventricular one.
Nicky said: 'It was a long operation and difficult, due to the blocked and narrow arteries. But it needed to be done, as the previous one wasn't working properly.'
Sarah has been trouble-free for almost three years, although she undergoes six monthly checks at Great Ormond Street and recently has been referred for further tests at Kings College Hospital for a possible neurological problem.
The teenager said: 'I still have to take warfarin every day to thin my blood so it can travel through my valves.
'I have to be very careful not to cut myself as it can cause heavy bleeding. But other than that I feel great.'
The ambitious schoolgirl hopes to become a dietician because she remembers how much help she received after stomach surgery.
Sarah said: 'I had my stomach stapled to stop the food coming up and flooding my lungs.
'That meant I couldn't eat much, so I was all small and skinny.
'But the dietician gave me an eating plan and lots of high-fat milkshakes so now I look normal for my age.
'That got me really interested in nutrition.'
Sarah also loves cooking and is taking her food technology GCSE.
'My chocolate eclairs always go down pretty well,' she added.
Suzie Hutchinson, chief executive of the charity Little Heart Matters, said: 'Sarah is a reflection of the wonders of modern medicine.
'The way new surgeries and techniques have emerged means many more children may be able to grow up and lead full and happy lives with this condition.
'Every day is a challenge for Sarah, not only because of her ever-changing medical condition but her need to move towards an independent adult life.
'She is the most wonderful role model.'
Nicky now runs a helpline for the charity and the family often hold fundraising events to help other youngsters.
'I wanted to give something back and I hope Sarah's story will give other parents some hope and encouragement,' she said.
'It is possible to defy the odds and pull through.'