Jane Houghton, 46, suffers from the rare Mal de Debarquement Syndrome which causes sufferers to feel the effects of bobbing about on a rough sea.

She developed the condition during the trip to Palma, Spain, in June 2001, and struggled to get her land legs back.

Almost a decade later, the mother-of-one said the condition has devastated her life.

Mrs Houghton, from Warrington, Cheshire, said: "It's a similar sensation to walking on a mattress or a trampoline.

"Everything around me is rocking and rolling. Objects sway about and I'm constantly unbalanced.

"On a good day, it's like being on a calm sea, but when I get a bad day, I can barely stand.

"When I first got off the boat, we treated it as a bit of a laugh. I went out for dinner and the tables were bobbing about.

"After a couple of weeks, I started to get seriously worried. My doctor thought I could be suffering from motion sickness, and gave me tablets, but nothing helped.

"I was referred for an MRI scan. I was petrified that I had a brain tumour, but when the results came back clear, I convinced myself I was going mad, to the point where I started feeling suicidal. My doctor was baffled."

Oddly, the only time she stops feeling seasick is when she is travelling on a boat, plane or train.

After months of research, she eventually got a referral to the National Hospital for Neurology in London, where doctors confirmed that she was suffering from her rare condition.

Despite spending months carrying out balance exercises, nothing could relieve her of her symptoms, and experts believe her brain may have "locked" itself into thinking it is constantly in motion.

Professor Yoon-Hee Cha, a neurologist from the University of California, and the world's leading expert on the condition, said the condition was very rare.

She added: "Mal de Debarquement Syndrome is an under-recognised disorder, for which there is no cure.

"It can be devastating to the patients, usually women, who are often in the prime of their lives.

"Neurologists believe it is caused by an abnormality in the brain, but we will not know exactly what that abnormality is until we can fund and carry out further research."

© Copyright of Telegraph Media Group Limited 2010