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Deep Vein Thrombosis

In the past several months, a condition coined "economy class syndrome" has been widely publicized in association with long periods of air travel.

The purpose of this article is to provide you with information on the condition, its causes and prevention.

To begin with, let's clear up a misconception about the condition. "Economy class syndrome" is a term used to describe the medical condition, Deep Vein Thrombosis (DVT). "Travelers thrombosis" in this case, is a more accurate term for the condition.

What is Deep Vein Thrombosis?

It is the formation of a blood clot within deep veins, those in the lower limbs, resulting in partial or complete blockage of blood flow in the vein.

The condition can be resolved if it is recognized and treated properly. However, it can be fatal if the clot breaks off, travels to the lungs, and causes a pulmonary embolism.

How is it caused?

Medical authorities have determined that sitting immobile for long periods is one of many contributing causes of DVT.

When you remain stationary, your heart must overcome gravity in order to keep the blood circulating normally.

After long periods of immobility, particularly in the sitting position, deep veins can become compressed, narrowed or blocked, making it more difficult for the blood to travel back to the heart and causing it to become trapped in the feet or the legs. Subsequently, the blood clot starts circulating and can move up to critical organs such as the lungs.

DVT can also be caused by confinement to bed and injuries to a vein. It can also be a side effect of radiation therapy or surgery or occur during pregnancy.

Am I at risk?

Of the small number of people onboard an aircraft that may be affected by DVT, most of them are pre-disposed to it by associated risk factors. Although some groups are more prone to DVT, anyone who stays immobile for long periods may be at risk of developing it. Medical research indicates that factors, which may give an increased risk of blood clots in the legs, include:

Low risk factors:

  • Age
  • Obesity
  • Smoking
  • Being immobile for a few days (bed rest) before flying
  • Dehydration
  • Lack of exercise

Preventative treatment: Stay mobile -- Keep hydrated -- Wear support stockings

Medium risk factors:

  • Pregnancy
  • Hormone therapy including the use of oral contraception
  • Varicose veins
  • Diseases such as severe infection, some types of cancer, liver disease
  • Mild cardiovascular and neurological disease
  • Lower limb surgery or fracture
  • Paralysis of lower limb

Preventative treatment: See your Doctor who may advise you to take Aspirin (do not self-medicate) or wear graduated compression stockings.

High risk factors:

  • Previous episodes of blood clotting
  • Family or personal history of internal clotting
  • Heart failure
  • Major recent (within 6 weeks) surgery such as abdominal or pelvic surgery
  • Moderate cardiovascular and neurological disease

Preventative treatment: See your Doctor who may want to consider treatment.
Evaluate the necessity of the trip.

How likely am I to get it?

As stated earlier, DVT is not restricted to air travel or passengers seated in Economy class. Passengers from Business, First class and even pilots can develop DVT. Individuals seated in cars, buses, trucks or trains are also at risk. In fact, this disease can affect anybody who is immobile for any length of time. Although there is no cause for alarm, if you are in one of the risk categories or have previously had DVT, we recommend that you seek medical advice before flying.

Passengers are also advised to follow the recommendations described in this article.

How will I know I have it (signs and symptoms)?

The signs and symptoms of DVT vary and are not always apparent. When a clot forms in an area other than the leg or the arm, no apparent symptoms may be recognized.

Since leg cramps and thirst are common amongst travelers, they are not likely to seek medical advice on these symptoms alone. A visit to your doctor is however recommended when feeling any of the following after a long flight:

  • Pain and swelling of the legs or in the chest
  • Sharp pain in the foot
  • Tenderness and redness of the leg
  • Pain and soreness of the joints
  • Fever
  • Rapid heart beat
  • Sudden, unexplained cough
  • Vein feels hard, like a cord
  • Coughing up blood

What to do if I suspect I have it?

Immediately seek medical attention if some or any of these symptoms occur after a long flight or repeated flights. Inform your doctor of your travel and tests can be done accordingly.

How is DVT treated?

The most important part of the treatment is preventing the clot from traveling to other parts of the body. Your doctor will be able to determine what treatment is appropriate, if needed. When deep vein thrombosis is detected early, treatment is usually successful. If untreated, the condition can be fatal.

In some cases, deep vein thrombosis becomes a chronic condition, where patients continue to have pain and swelling of the leg because the thrombosis has damaged the blood valves in that vein.

Rubbing the affected area should be avoided as this may dislodge the clot. It is, however, recommended that the limb be kept elevated.

What to do if I had it in the past?

DVT will not cause complications and should not prevent you from flying when recognized and treated properly. If you had DVT in the past, it is very advisable that you seek medical advice before traveling.

How to prevent it

Providing extra seat space does not directly prevent the problem. A number of measures can be taken by passengers to avoid the condition, including:

  • When on a long flight (and if possible on any flight), always try to move your ankles, toes and legs regularly. Exercising and stretching increases blood circulation and minimizes the risk of DVT. Exercises should be done every hour for a few minutes;
  • Cabin luggage should be kept to a minimum in order to leave the area under your seat empty to enable stretching (although for shorter passengers whose feet do not reach the floor, it is recommended that feet are elevated, using luggage if necessary, in order to prevent the seat edge from compressing the back of the thighs);
  • Since humidity in an aircraft cabin is usually very low, your body is more prone to dehydration. Being diuretics, it is advised, if you are at risk, that alcohol, coffee and tea be avoided. Water or juices are a better choice and drinking plenty of them during your flight will keep you well hydrated;
  • Avoid taking sedatives before and during a flight in order to refrain from sleeping and be able to move freely.

Remember that problems do not develop in the vast majority of air passengers, even though they are in a confined space for long periods of time. It is however recommended that these guidelines be followed in order to minimize your risk of developing DVT.

How can I get more information on the subject?

In order to find out more about DVT, you can contact your physician or visit the following Web sites: