An Airedale Hospital worker was rushed to the accident and emergency department when colleagues suspected she had deep vein thrombosis following a long-haul flight from Australia.

Mary Wickens, a domestic assistant at the hospital, returned from a three-week stay in Australia over New Year. A few days after returning home to Sutton from the 23-hour flight, she began to feel unwell.

"It started last week, it was like muscle pain. I thought I'd just strained a muscle in my left leg but it suddenly got a lot worse," she explained.

"I rang a friend, who spoke to one of the consultants and went straight round to the A & E department, where they said I had a deep vein thrombosis. I didn't really know much about it so I was very worried."

Deep vein thrombosis (DVT) is the formation of a blood clot within a deep vein, usually in the thigh or calf, which either partially or completely blocks the flow of blood.

It has been dubbed "economy class syndrome" because the economy seats on a plane have less leg room, restricting movement on long flights.

However, it is not confined to economy class or to long-haul flights.

Certain people are more vulnerable, including pregnant women, women who have recently given birth, women taking the contraceptive pill, women on hormone replacement therapy, people who are overweight, the elderly, smokers and those with coronary artery diseases and certain blood conditions.

Mrs Wickens said: "I am on HRT and visited my doctor beforehand. I took some aspirin before the flight but I still got it. I am still very unwell with it and have had to have lots of injections.

"I'll be on medicines for the next three months, and they say that once you've had one you're more likely to get it again in the future. I just want to warn people about it and to tell them to be very careful and look out for the signs."

The common symptoms include tenderness and redness in the affected area with pain and swelling, fever, rapid heart beat, a sudden unexplained cough, joint pain and soreness.

DVTs themselves are not life-threatening, but they are associated with complications which can be fatal.

The most common serious complication is a pulmonary embolism, when a piece of the clot becomes lodged in the lung.

More rarely, a part of the clot may also lodge in other organs, including the brain, where it leads to a stroke.

Most people with a DVT need to be cared for in hospital in the initial stages to dissolve the clot and prevent other clots from forming.

The main treatments for DVT are medicines which thin the blood and allow it to flow more easily.

When taking these blood-thinning drugs, patients usually have regular blood tests to make sure they are getting the right dose and are not at risk of a haemorrhage.