Ask business travellers if they have any fears about flying, and Economy Class Syndrome may have moved up to the top of the list after all the recent publicity over blood clots that can be brought on by long flights in cramped seating. Frequent flyers are, simply by the law of averages, more at risk, but what about the pilots themselves, who spend most of their working hours in the air, often in the cockpit for more than 10 hours? A Cathay Pacific pilot tells me he and his colleagues are becoming more aware of the need to take precautions to protect themselves from falling victim to the syndrome, medically known as deep vein thrombosis (DVT). 'I pilot 747-400s on long-haul flights, and the conditions in cockpits are certainly a bit cramped,' he says. 'We have relief crews on long journeys, so when I'm not at the controls I spend a fair bit of time doing stretching and bending exercises at the back of the cabin. 'I know medical experts advise passengers to walk around as much as possible, but of course pilots don't like to stray far from the cockpit. 'On a long-haul flight, the cockpit crew drink a total of around four litres of water to prevent dehydration, which it is believed can contribute towards an attack of DVT.' He also says he knows that other pilots have died from DVT, one after a blood clot went to his brain (none of them worked for Cathay). 'They call it Economy Class Syndrome, but DVT can also hit Business Class passengers, who become complacent because they have comfortable seating,' says the pilot. 'In economy class with some airlines, passengers are so squashed up that they get up and walk around every couple of hours to stretch their legs. 'A problem in Business Class is that passengers get so comfortable in wide seats that offer plenty of legroom that they just sit there throughout the flight and watch their personal TV. They need to exercise, too.' Of course, more spacious seating, when complemented by regular exercise, may help prevent attacks of DVT. There is a new, independent Web site which gives a rundown of the seat pitch (space between rows) of major airlines worldwide. Check out travel.simplyquick.com The site looks at many aspects of air safety. In a survey of US airlines, Northwest and Continental get low marks for seat pitch, though Northwest comes out as the best airline in the US overall. Worldwide, British Airlines and KLM also get black marks, while those who score highly for seat pitch include Thai International, Singapore Airlines, Air New Zealand, Alitalia and Emirates. Cathay Pacific's seat pitch is regarded as acceptable. I suffered DVT myself a couple of years ago after a flight from Europe. Now I make sure I walk around regularly during long flights, and have cut down on coffee and alcohol inflight, drinking lots of water. Even if I am flying Business Class, I go for a walkabout through economy, to the rear of the plane, several times. I was lucky. Blood thinning tablets helped dissolve the clot in my calf. Clots that move to the heart or lungs can prove fatal. But when the clot dissolves, the problem is far from over. Victims must take blood-thinning tablets, often for months, to prevent a recurrence. While the tablets prevent DVT from recurring, the victim has to be very careful not to cut himself, for he could bleed profusely, and regular lab tests must be made to ensure that the clotting time is kept within a tight range. The diet must also be strictly controlled, and certain vegetables can't be eaten because they are high in vitamin K, which encourages clotting. My blood has returned to normal now. If you suffer from a swollen calf for no apparent reason within days of a flight, seek medical attention at once. My condition was incorrectly diagnosed at first. Any doubts, ask to have an ultrasound scan.