Medicine Cabinet: Deep-vein thrombosis

You've got your passport, boarding pass, euros, pesos or pounds. You've made it through security and have your shoes back on. But before you claim a seat in the waiting area, take a walk. And if you're over 40 and your flight time is more than four hours, stroll the plane aisles every couple of hours. Long flights (include tarmac time), cramped seats (especially window seats) and being older are all risk factors for the infamous threat that frequent fliers call economy-class syndrome. Doctors call it deep-vein thrombosis (DVT) - a blood clot in a deep vein.

There's no proof that walking around the cabin prevents DVT, but it can't hurt. Neither can doing those anti-clotting plane-seat exercises found in many in-flight magazines. Why? When you're immobile, blood flow slows, and clots may form. That can cause scary problems if, say, a clot gets loose and gets into your lungs. If that happens, forget your trip.

Here are other common-sense tips to pack in your "can't hurt, could help" carry-on:

Take two baby aspirins or half a regular one with a glass of water before boarding to make your blood platelets less sticky. (We think just about every man over 35 and woman over 40 ought to be on daily aspirin, anyway, but check with your doc on this.)

Drink water to stay hydrated.

Skip alcohol if possible; definitely don't have more than one.

Wear compression stockings.

Relax and enjoy the flight; stress encourages clotting.