Jessie J looked like ''Shrek's little sister'' when medication turned her skin green.

The 25-year-old star suffered a major health scare as a child when she was diagnosed with an irregular heartbeat, and she reveals that one of the drugs used to treat her illness had an unusual aftermath.

She explained: ''When I was nine, I was diagnosed with an irregular heartbeat and was prescribed beta blockers which had the side effect of turning my skin green. Looking like Shrek's little sister at school wasn't the easiest thing. I had various procedures to try to correct my heartbeat.''

The 'It's My Party' singer's ailments forced her to change everything from her eating habits to her daily routine at a young age, so Jessie was well prepared when she was struck by another medical emergency in her teens.

She told the Metro newspaper: ''I had to learn at a young age to adapt my lifestyle to make the chances of getting unwell slim. When I was 18, I had a minor stroke in Hamleys [toy store] of all places, but I had learnt how to deal with an unexpected health scare and just focused on getting better immediately.''

Jessie now uses her music as a way to inspire other youngsters experiencing similar health scares and hopes she can prove there's light at the end of the tunnel.

She enthused: ''I'd always written poetry and it was at this time that the poems started to take on the shape of songs and I realised that all the things that had happened to me had happened for a reason, and I had to use them in a positive way to inspire other young people to push through their problems and pursue their dreams.''