What is deep vein thrombosis (DVT)?

People who have a history of cardiovascular disease, stroke or thrombotic episodes (blood clots) are at risk of getting blood clots in their legs during airplane flights of 10 hours or more.  But these aren’t the only people who can have this problem.  This condition, known as deep vein thrombosis (DVT), also can affect healthy people, even athletes.

What is economy-class syndrome?

Developing DVT after long plane rides is often called “economy-class syndrome” or “coach-class syndrome,” because seating and leg room are particularly cramped for passengers in economy class.   However, first-class and business-class passengers also get DVT, so this problem isn’t solely due to sitting still in tight quarters for many hours.  Other factors -- such as low cabin pressure, low humidity and dehydration -- all may contribute.   These factors are constant throughout the plane.

Why is deep vein thrombosis dangerous?

DVT is potentially life-threatening.   In it, blood clots form in the body’s deep veins, particularly veins in the legs.  Sometimes the clot breaks off, travels through the bloodstream, and obstructs a vessel in the lungs, restricting blood flow.   This condition is called pulmonary embolism.  This damages tissues and causes poor lung function, which can be fatal.

People who survive their first episode of DVT may have chronic swelling in their leg and pain from the blockage of blood flow through the vein.  This can reduce their ability to live a full, active life.   People who’ve had one DVT episode are also prone to have more.

How do I prevent DVT during air travel?

Studies in healthy people have shown that wearing “compression stockings” may help minimize the risk of developing DVT after long flights.  These stockings put pressure on leg muscles and help return blood flow from the legs to the heart.

People with cardiovascular disease and those at risk for clots in their legs may benefit from a single dose of heparin.  This drug prevents clots from forming and is effective in reducing the risk of DVT in high-risk patients.

Drinking extra water, walking if feasible and avoiding alcohol intake are also good advice.  These steps aren’t scientifically proven to prevent traveler’s thrombosis, but they’re common sense.  

See the Related Items box above for links to the Cardiology Patient Page in Circulation, Journal of the American Heart Association:

• Diseases of the Veins
• Pulmonary Embolism and Deep Vein Thrombosis
• Treatment of Blood Clots