Deep-Vein Thrombosis

Introduction

Deep-Vein Thrombosis (DVT) is a condition rather than a disease state caused by an outside vector (bacteria, virus, fungus or parasite). It can also be prevented in most cases. It is of great importance to people who spend several hours at a time traveling on buses, in cars or on airplanes. DVT is, simply put, the formation of blood clots (thrombi) in the large (deep) veins of the body. For travelers, the veins located in the pelvis and legs are most commonly affected. DVT can occur whenever blood flow is restricted and sitting in cramped conditions for several hours at a time definitely can restrict blood flow (think legs and feet that "fall asleep" - that's restricted blood flow).

In order to understand the seriousness of DVT, it is important to remember a small bit of basic biology:

• Veins return oxygen-poor blood back to the heart from the rest of the body.
• The heart pumps this blood into the lungs to absorb more oxygen.
• The blood is returned to the heart, rich in oxygen, and is then pumped to the rest of the body through the arteries.
• The largest vessels are also the deepest vessels within the body.

Yes, there is a whole lot more to it, but I did say "basic". Since deep veins are also large in size, the blood moves more quickly and at a greater volume through them. Because of this, when one or more blood clots form in a deep vein, they have a greater potential to break free of the venous wall and be carried to the lungs through the blood stream. When they break free the name changes from thrombi to emboli - but a clot is a clot is a clot. Once a clot enters the lungs, it can lodge in one of the smaller vessels causing a blockage (pulmonary embolism) and the death of lung tissue. If a clot should lodge in one of the heart's coronary arteries it can cause an infarction (heart attack). The problem with DVT is that clots begin to form during the period of decreased blood flow - that time sitting on a plane for 4 hours or more - but may not break free until days, weeks or months later. It is the amount of activity following the long flight or bus ride that can set the wheels in motion. Increased activity means increased heart rate which means increased speed and volume of blood moving through the deep vein.

It should be understood that DVT is uncommon in a normally healthy individual under 40 years of age. Those who develop DVT from travel-related situations usually - though not always - have underlying risk factors, such as smoking, high blood pressure, oral contractive or replacement estrogen use, pregnancy, surgery, venous injury, previous prolonged bed rest, or inherited clotting disorders among others.^{[1][2][3][4][5][6]}

Prevention

During Long Travel Periods

• Walk up and down the aisles of planes, trains and buses periodically.
• If traveling by car, stop every 1-2 hours and "stretch your legs" by walking for a few minutes.
• Use flex/stretch motions to exercise the calf muscles in the legs and increase blood flow.
• Wear loose-fitting clothing.
• Drink plenty of fluids and avoid alcoholic beverages.
• Wear compression stockings to avoid fluid retention and swelling of the lower legs.

General Preventative Measures

• Maintain a healthy weight.
• Do not smoke.
• Restrict alcohol consumption.
• Take all prescribed medications as directed.
• Have regular check-ups to maintain your health and detect possible risk factors.^[7][3][8]

Symptoms and Treatment

Symptoms

The symptoms of DVT are not always evident. It has been suggested that almost half of the cases of DVT never present with "classic" symptoms and go virtually unnoticed. For those cases that do present with symptoms, they are:

• Swelling of the affected limb(s), most commonly the legs, which can include the ankles and feet.
• Leg pain, which feels like a muscle cramp (charley horse), originating in the calf area and may include the ankle/foot. The inside of the thigh may also be affected.
• Redness and/or warmth developing in a certain area of the leg.
• Any or all of the above symptoms developing in the arm(s) and/or neck area.

If a deep vein thrombus (clot) has broken free and become lodged in the pulmonary system (pulmonary emboli), the sysmptoms include:

• Chest pain and/or discomfort. Taking a deep breath or coughing usually makes the symptom worsen.
• Shortness of breath.
• Lightheadedness, dizziness and/or fainting.
• Unexplained anxiety or nervousness.
• Blood upon coughing.^[1][9][10]