Jane Elliott BBC News Online Health Staff

As thousands of holidaymakers take to the skies, one woman is anxious to warn them about the dangers of long-haul travel.

Former landlady Val Clark admits she was blissfully ignorant of the dangers of deep vein thrombosis (DVT) when she set out with friends for a holiday in the US.

But cramped conditions on the return flight led to blood clots, a lengthy spell in hospital and the eventual loss of her leg.

She successfully sued North West Airlines and last year accepted an out of court settlement following her ordeal seven years ago.

Val Clark needed to have her leg amputated

But Mrs Clark, of Gateshead, said she is desperate to warn others of the dangers of flying long distances without taking sensible precautions.

"I didn't know that because I was taking hormone replacement therapy that I was at a greater risk. I don't think anyone knew this then.

"But now there is a chance for others to prevent it."

I could not walk, my legs were numb and I was in pain

Val Clark

Risk

Medical research has shown that clots develop in blood vessels deep in the legs when circulation slows - when people remain seated for long periods, for example.

The clots can prove fatal if they break off and are carried to the lungs, blocking the flow of blood.

Several medical reports have claimed a link between DVT and air travel, although it is yet to be proved.

Preventing DVT

Taking a low dose of aspirin before a long flight Foot exercises such as rotating the ankles and wiggling the toes Wearing compression stockings may be advised for those at risk of developing a DVT Special foot cushions have been developed so passengers can exercise while sitting at their seats Keep mobile

Mrs Clark said that the first leg of her return journey from Arizona had been fine, but when she got on the second flight from Minneapolis to Amsterdam she was forced to sit in very cramped conditions.

"There was no room for the hand luggage and I had to sit on my bag for the entire flight.

"I asked them to move the bag, but they said there was no room in the lockers.

"I have flown all over the world and have had no problems. I have been to Thailand three times, including once that year."

Vital signs

But just two days after her US flight Mrs Clark started to suffer serious problems.

Her feet were swollen and sore, but because Mrs Clark had never heard of DVT she missed the vital signs.

She then started suffering from excruciating pains and needed to be rushed to hospital.

"I could not walk, my legs were numb and I was in pain.

Ultrasound is used to detect clots

"I was rushed to hospital and needed to be resuscitated twice."

Six weeks later she was released from hospital, but her legs became worse and just before Christmas 1995 she was brought back in to have her leg amputated.

"Even though they had taken all the clots away my legs were swollen and I needed to have the leg amputated."

Even now Mrs Clark cannot fly - she takes the car or ferry for every trip and suffers from almost constant pain.

"I have ulcers on the bottom of the wound where the skin is too thin.

"I can't work and if it wasn't for my hobby making three dimensional pictures I would be suicidal.

"I have run pubs for the last thirty years, but I now feel stagnant."