THE CARDIOVASCULAR INSTITUTE

DEEP VEIN THROMBOSIS (DVT)

With the coining of the term "economy class syndrome," more people are becoming aware of deep vein thrombosis (DVT), a condition that can be caused by prolonged inactivity. DVT refers to the formation of a blood clot, or thrombosis, in one of the body's deep veins, often a vein in the calf or thigh. Blood in these veins moves somewhat slowly, particularly with lack of exercise, and as the blood pools a clot can develop. As the clot grows, pieces can break off and travel to the heart or lungs, causing serious and sometimes fatal complications.

While long trips that require sitting for several hours can contribute to the risk for DVT, some people are more at risk of developing DVT because of other factors. Fortunately, everyone can take steps to prevent it.

Recognize warning signs and risks

Sometimes DVT causes symptoms, such as chest pain that worsens with deep breathing, pain in the calf or leg, swelling of the leg, rapid pulse, sweating and shortness of breath. But often there are no warning signs. It is therefore important to know if you are at risk and to take action if you are. The most significant risk factors include:

• Prolonged bed rest required after major surgery or during a major illness such as the flu; the risk for DVT is especially greater for older adults who remain more immobile and can become dehydrated
• Certain cancers, such as those in the pelvis and abdomen, which release substances that can cause the blood to clot more easily
• Anyone known to have an inherited tendency for clots
• Pregnancy and the use of birth control pills are risks as well, although less significant, as is air travel. However, if you have had DVT, your risk of getting it again on a long flight is very significant.

Take action

Fortunately, there are some simple steps you can take to prevent DVT. For example:

• Stay well hydrated with water, not alcohol. Dehydration thickens the blood and may increase the risk of clots. Alcohol is actually dehydrating. The air inside planes is particularly dry, and therefore you should drink plenty of fluids.
• Try to get up and walk every hour.
• If walking is not an option, as on some flights, a few simple leg exercises will work. For example, while seated, with your feet flat on the ground, raise your heels and squeeze your calf muscles. Do this 10 to 15 times an hour or more. The more the better.
• If you are at highest risk for DVT, tell your doctor before a long trip. He or she may prescribe a medication that reduces the chance of clotting.