Sufferers of ME, known as Chronic Fatigue Syndrome, are used to the views of sceptics who believe the problem is all in the victim's head and those who think it is just about feeling tired. Try telling Lynn Gilderdale that.

The 28-year-old has not been able to leave her bed for 14 years and communicates with her family through sign language.

As a talented teenager, Lynn Gilderdale never sought attention.

Living in the small village of Stonegate, near Heathfield, she kept busy with her hobbies and had three best friends with whom she was very close.

She played the clarinet and piano, swam, won prizes for ballet, became school netball captain and regularly visited Stonegate youth club and the Swimming and Sailing Club in Eastbourne.

In November 1991, aged 14, she faced the day many teenagers dread, the BCG injection at school.

Lynn queued up, got her jab and went home but quickly began to feel ill. The following day was to be her last at school.

Her immune system was unable to cope with the live virus in the injection, she did not produce the necessary antibodies and she began to develop illness after illness flu, bronchitis, tonsillitis and glandular fever. The illnesses left their physical toll.

Her legs would sometimes give way, she was in pain, sometimes fainted and her memory was suffering.

By May 1992, six months after the injection, Lynn was diagnosed with ME (myalgic encephalomyelitis) disparagingly termed "yuppie flu" by those who did not know any better.

Doctors at a clinic in London were specialists in the syndrome but Lynn felt she was treated as an attention seeker with a made-up illness.

Her mother, Kay, 52, said: "We were accused of all kinds of things because of the disbelief.

The doctors started saying 'stop pretending, you can do this, you can do that', trying to make her do what she couldn't do."

Although she could not swallow and spoke only in a whisper and failed to recognise people, she continued to undergo punishing experiments.

She was given a truth drug, asked if she was abused at home and left alone to see if she would get up for the toilet, in a series of cruel but perhaps well-meaning experiments to try to snap her out of her condition.

Her GP, though supportive, was not equipped to help and her parents decided in August that year to take her home.

Doctors told them Lynn could die if they removed her but after watching her deteriorate in their care, Kay and Richard Gilderdale felt she would be safer, healthier and happier at home.

Fortunately, they were right and Lynn is relatively much better than she was.

At her worst, she could only move her little finger, could not recognise anybody, remember anything, remained in terrible pain with muscular spasms and shook all over.

She could not bear any light, touch or noise. She could hear only one whispered voice at a time.

Now home care and a lot of drugs quell the symptoms of her ME and she has adapted in clever ways.

Her brother, Steve, who lives in Belgium as an IT manager, visits about once a month with various technologies which aid Lynn's quality of life, allowing her to listen to Robbie Williams or stories on her iPod and take photos or email from her bed.

Her best friends, a doctor in New Zealand, a solicitor, and an IT manager, all keep in touch with their old schoolmate.

Most of the time she keeps company with her parents and Ollie, her persian cat, who guards her bed.

Kay, who was an auxiliary nurse for 11 years, is her full-time carer, visited at least daily by ex-husband Richard, a former Sussex Police inspector now working for the force as a civilian.

They broke up, says Kay, because of unrelated problems but have found a way to become friends again by spending time looking after Lynn.

Lynn is able to communicate her feelings through a system of sign language she has developed herself.

It is a natural and unlearned method, as she cannot remember anything for more than a few hours, but she has taught her family and carer what she wants.

Kay said: "She's very intelligent and that's there still, even though she can't read or write.

It doesn't make her depressed in the true meaning of the word, though she's sometimes sad and gets low when she's been in hospital for a month-long spell without any food, just on a drip.

"But she's never depressed, we have even discussed it and if she ever was we would look at treating that."

But Lynn still sleeps 16 hours a day and never goes outside except on the way to hospital twice a year. Being bed ridden brings its own medical problems.

She often has blood clots and severe osteoporosis, irritable bowel syndrome and asthma and is always fed through a tube. Recently she was taken to the Conquest hospital in Hastings to have her Hickman line replaced.

She receives medication through the line but suffered complications, a punctured lung.

After suffering breathing problems for two weeks and being put on oxygen, doctors discovered her lung had collapsed and the other lung was almost flat.

She had two litres of blood pumped from her lung, was taken to Kings Hospital in London and put on a life-support machine for two weeks.

Lynn is among the 25 per cent of ME sufferers who have such severe symptoms and there are no known cures.

The family take heart from stories of those who have suddenly recovered from the virus and Kay is online every day keeping up to date with research into the syndrome.

There are trials due to take place by the end of the year based on gene expression research, which would mean Lynn taking Beta Interferon, a drug usually prescribed for MS sufferers.

But being unable to make it up to London for tests may rule her out of the trial.

Stem cell research is another possibility and a network of families of ME patients are in regular contact to share their news. The Gilderdales are not religious.

Kay says she cannot understand how there could be a God who could allow this sort of suffering but she is grateful for their religious neighbours who pray for Lynn.

The small village of Stonegate has been very supportive of the family.

Villagers help out if the family need anything but for the most part Kay is there full-time, with a carer who visits two mornings a week while Kay does a little shopping or runs her errands. She keeps her humour because she has hope and because Lynn cheers up everyone around her.

When asked if she was fed up with her illness, Lynn signed: "Just a bit," and when her mother is tending to her when she is vomiting, she will lighten the mood by signing: "Nearly got you that time!"

Kay was only 37 when Lynn fell ill and has little social life of her own but she gets on with looking after her daughter with a patient smile and says it has taught her an important lesson about dealing with doctors.

She said: "In the beginning we relied on doctors having all the answers for us and put total trust in them but once we got to the point where they said if you take her home she could die, we realised you have to rely on yourself.

"If I went to the doctors for depression they wouldn't be able to cure it. "They haven't got all the answers, you have to make your own life easier."