Holly Pereira, 19, made the clip in which she tells of living with cystic fibrosis, a life-threatening disease.

It means she has only 20 per cent of normal lung capacity and struggles to do everyday tasks.

The condition forced her to move back in with her parents at their country house in East Sussex.

She has spent three months on the transplant waiting list and may have to wait another 18 months for vital organs.

But unless Holly gets new lungs soon, her lift could be cut short.

Talking straight to the camera in the black and white clip, Holly admits: "There is nothing I can do.

"[I] hope that my call will come because sadly I know sometimes it's too late and the call doesn't come in time.

"Having little lung function means doing the small everyday tasks like showering and walking a lot more difficult as I get out of breath very easily," she explains.

"It may mean I have only a years left to live. Due to the lack of organs available, I may find it hard to find a suitable donor."

Almost 41,000 people have viewed the video since Holly posted it in early July - with telling her parents.

Her grandfather David Nicholson, 67, admitted he burst into tears when he watched the clip.

Several viewers were moved by her YouTube plea and inspired to sign up as organ donors.

ChillingOutOnTheHill wrote: 'Holly, because of you, I have now registered. My prayers are with you. If I could help someone I will. Thank you. You are an angel.'

Cystic fribrosis is an inherited condition affecting the organs, particularly the lungs, and digestive system.

Every week in the UK, five babies are born with the condition. More than 9,000 people in the UK live with the condition.

Around one in 25 of the population carry the gene and the child of two carriers has a 25 per cent chance of being born with cystic fibrosis.

Half of all sufferers die by the age of 41. But advances in treatment mean babies born today have a much longer life expectancy.