Each day we must all travel from one place to another and, regardless of the means of transportation we use, it will involve sitting for long periods of time in a car, bus or airplane, many times for over four hours. Believe it or not, being in this position for a prolonged time may cause serious consequences to your health.

Deep Vein Thrombosis (DVT), or "Tourist Class Syndrome", is a medical condition linked to prolonged sitting during long trips in which a blood clot forms in large vein (usually in the leg). The main concern is that sometimes these clots may break away and travel through the bloodstream, making their way to vital organs such as the lungs and heart and causing serious conditions, such as pulmonary embolism, or even death.

The death of 28 year-old Emma Christofferson when flying back home to London in October, 2000, was one of the cases regarding DVT that made headlines around the world. Christofferson was traveling from Australia to Great Britain and after disembarking from the 20-hour flight she collapsed at the airport due to a deep vein thrombosis.

Although this was an extraordinary case, some people are at higher risk of developing DVT. Whether it is due to certain medical conditions, their level of physical activity or to medications they might be taking, these factors may alter normal blood-clotting mechanisms. Some of the most common risk factors are:

• Pregnancy, oral contraceptive use or hormone therapy
• Cancer
• Blood-clotting disorders
• Increasing age (the risk increases over the years)
• Smoking
• Prolonged immobility, due to long hospital stays, long trips or in bed-confined patients
• Obesity and/or heart disease
• Recent major surgery or injuries

Everyone should be able to recognize the symptoms that accompany a DVT episode (although many times no symptoms will occur). Among the most important, there might be pain, swelling, tenderness or redness of the skin over the affected area (usually, the legs). If you also experience trouble breathing or chest pain, seek help as quickly as possible since this may indicate that a clot has traveled to the lungs.

If you know when you will be traveling, it is recommended that you exercise the day before or the morning of your trip (which will also help your body adjust to the time change at your destination). In addition, drink plenty of water and other fluids before and during your trip, avoiding alcohol and caffeinated drinks since these are diuretics that will dehydrate you. Travel with loose-fitting, comfortable clothing and, ideally, wear elastic compression stockings to improve blood flow back to the heart.

Being aware of the risk factors and symptoms associated with this condition will allow you to be even more alert during long trips and identify if you or someone nearby may be having a deep vein thrombosis. If so, seek help immediately. And remember: prevention is key and, in this case, simple measures such as regular exercise and staying hydrated can be the difference between life or death.