Dr. Eric Anderson, a charter diplomat of the American Board of Family Practice and a former president of the New Hampshire Academy of Family Physicians, is a regular contributor to Travel Tips 'n' Tales. He is widely traveled and published, having written a travel health column for Travel 50 & Beyond and a weekly online column, Ask The Doctor, for The New York Times Syndicate. Dr. Anderson invites you to send your questions regarding travel health issues to ericmd@lorrypatton.com

Q: My parents are in their early seventies and are making their first long haul flight (10 hours) in 16 days time. They are both in very good health although my father has a touch of arthritis and varicose eczema on both legs. This means that after periods of sitting his legs get very stiff.

Apart from buying him special socks, advising him to drink lots of water and to regularly stretch his legs, I was wondering if you could give me any more advice, as I worry terribly about him. He is hopefully going to have a bulkhead seat but this cannot be guaranteed and he may end up with a normal economy seat.

Kate

A: I can understand your anxiety. There has been a lot of talk recently about the cramped seating in airliners today and the incidence of pulmonary embolism where blood clots go from passengers' leg veins to injure their lungs.

Blood clots in travelers is not a new issue: It has long been known that sitting a long time in automobiles can create the same problem. A physician in Albany, NY once reported blood clot admissions to hospitals along the NY Thruway increased the further west drivers went nonstop from NYC. So sitting anywhere for a long time -- with legs bent and veins behind the knee compressed -- puts people at risk.

Australian physicians are especially interested in this matter as Australians have to travel so far to get to Europe and the United States. Their studies show the incidence of embolism increases after journeys of 3000 miles and, especially, 6000 miles. Another way of saying this is: flights of longer than 12 hours carry increased risk. Although airline embolism has been tagged "Economy Class Syndrome" it statistically affects equal numbers of first, business and economy passengers. It's the distance that seems important and whether the traveler has other risk factors.

In one evaluation the incidence doubled after the age of 70 compared to the rate for those aged 60. Males and females were equally affected. Obesity is another concern as is pregnancy, being on hormone replacement or birth control pills, having a family history or personally having had a previous episode of blood clotting or attacks of heart failure or recent leg injury or pelvic surgery. Prior prolonged bed rest predisposes to embolism as does sickle cell anemia and cancer.

It's taken time to get to the point, Kate, but once we understand the risk factors we can see what might be helpful. The bulkhead seat may not be the answer if it's too close to the actual wall in front. Sometimes the space below the seat in front of any row allows legs to be stretched out more than a bulkhead seat. It's not likely that Dad would be able to convince the airline desk that he should get an exit row. American Airlines does have more room in economy than most airlines but word is it may be reconfiguring its seats back to the tighter industry standard.

Some of this you have mentioned. He can walk each day before the flight as much as his arthritis allows. Swimming and dancing are alternative activities for those with more time before they fly. He should wear loose clothing -- like sweats -- and wander around the airport lounge until he boards the plane (the walking stimulates venous return to the heart whereas sitting in the lounge or standing there lets it pool in the legs).

He should drink plenty water for the few days that precede the flight and during it. He should avoid smoking and alcohol during the flight. Some doctors feel if there is no contra-indication to aspirin he might take one adult aspirin the day before and the day of the flight but this is controversial because of aspirin's side effects. One study of 13,000 patients who had undergone hip surgery showed the incidence of post operative pulmonary embolism dropped 43 percent when patients took aspirin for four weeks after surgey. Most physicians feel that good quality elastic compression stocking make a difference, too, but if your father has varicose eczema he probably already wears them.

The benefit of walking around the cabin at intervals has to be considered in light of the possibility of turbulence when passengers strapped in their seats clearly are safer then those in the aisle. While seated he should do exercises and massage his ankles and calves and move his legs occasionally and try not to sit for periods with his legs crossed. A study of 135 million passengers who arrived in Charles de Gaulle Airport in Paris found 56 patients who had to be hospitalized with pulmonary embolism and, of those, only three said they vacated their seats and walked the aisle during the flight. So walking around the cabin seems to be helpful - and, note the numbers: the incidence of this problem is not high.

That is an important final point. A British study suggests that "white knuckle passengers" are more at risk of pulmonary embolism because their nervousness causes adrenaline release with its increased risk of blood clotting. So what we need to do with your parents is make helpful suggestions but not so overstate the concerns that we frighten them and ruin what is presumably going to be a great vacation.

Bon voyage!

NOTE: Lorry Patton's Travel Tips 'n' Tales would like to remind you to always consult with your personal physician before following any medical advice and to please read the Travel Tips 'n' Tales "Terms of Use" found on the bottom of each page of this website. Dr. Anderson's opinions are not necessarily the opinions of Lorry Patton or Travel Tips 'n' Tales.