Deep vein thrombosis (DVT), the formation of blood clots in the lower limbs, is usually due to immobility and a sluggish circulation. DVT is an increasingly common condition suffered by airline passengers due to cramped seats. It is estimated to affect over 30,000 passengers worldwide each year. These figures do not include other flight-related problems such as heart or cerebral conditions (strokes, seizures, migraine headaches, etc.).

Clots that develop in the deep veins of the leg can be life-threatening because they can break off and block important arteries, thus denying oxygen to vital organs like the lungs, heart, or brain. Heart attack, stroke, and/or sudden death are the potential consequences.

Although at least 10 studies have pointed to a direct link between air travel and thrombosis, the International Air Transport Association (IATA) claims that there is “no conclusive medical evidence.” Law suits against airlines in Great Britain and Australia have recently been launched (March, 2001) in an effort to compensate victims of this so-called “economy class syndrome”—a.k.a. "travelers’ thrombosis." First class passengers are less likely to suffer from DVT, supposedly because they have more legroom than economy class passengers.

In response to the growing concern over “economy class syndrome,” British Airways now recommends the following common sense steps to prevent blood clots with air travel:

• Drink adequate fluids. Dehydration increases blood clotting risk.
• Avoid smoking, a well-known blood clotting stimulant.
• Avoid alcohol (although most airlines offer alcohol in flight).
• Avoid crossing legs when seated.
• Walk around the cabin when you can. Activity improves circulation.
• Stand up in your seat area, and stretch your arms and legs.
• Wear loose-fitting, comfortable clothes when traveling.
• Seek medical advice before traveling if any known history of DVT, recent surgery, or other risk factors.

Hypercoagulability, an increase in the tendency of the blood to clot, can occur in people who have genetic conditions called protein C or protein S deficiencies. If you are uncertain whether or not you suffer from these conditions, ask your doctor to test you for them.

Some other factors that increase one’s risk for DVT are:
• Obesity
• Constrictive clothing that squeezes the upper thighs
• Alcohol (leads to dehydration, increasing the coagulability of the blood)
• Birth control pills
• Hormone replacement therapy

Blood clots in deep veins can be the result of:
• Injury
• Steroid drugs
• Tobacco use
• High blood fats
• Some cancers
• Cancer chemotherapy
• Immobility
• Lack of antioxidants manufactured in the body in response to oxidant stress

Lifestyle changes like the elimination of tobacco use, more exercise to improve oxygenation and circulation. and diet changes are all positive things that can be done to prevent blood clots.

Check my next blog for the nutritional approach to reducing the risk of DVT.

Dr. Zoltan Rona

Dr. Zoltan Rona