Sitting still, cramped in an airplane for a long flight can be dangerous. Immobility, low cabin pressure and dehydration can lead to "economy-class syndrome," a condition causing blood clots to form in the veins of the leg, even if you're flying first class.
A blood clot in the vein (called deep vein thrombosis) can be life threatening when the clot breaks off, travels through the bloodstream, and obstructs a vessel in the lungs, restricting blood flow.
Blood pressure is the force of your blood pushing against the walls of your arteries. Each time your heart beats, it pumps out blood into the arteries. Your blood pressure is highest when your heart beats, pumping the blood. This is called systolic pressure. When your heart is at rest, between beats, your blood pressure falls. This is the diastolic pressure.
Your blood pressure reading uses these two numbers, the systolic and diastolic pressures. Usually they are written one above or before the other.
Some people have low blood pressure all the time. They have no symptoms and their low readings are normal for them. In other people, blood pressure drops below normal because of some event or medical condition. Some people may experience symptoms of low pressure when standing up too quickly. Low blood pressure is a problem if it causes dizziness, fainting or in extreme cases, shock. Low blood pressure may also increase the risk of stroke during surgery.
Source: National Heart, Lung and Blood Institute
Medical evidence suggests that travel-related blood clots are relatively rare, occurring in 1 in 5,000 persons according to the evidence-based medicine website, Bandolier.
"The blood cools in your legs and becomes a little static because you're not up and walking around, squeezing the veins and making your blood move," warns Dr. Kent Dauterman, with The Heart Clinic of Southern Oregon and Northern California. "If you're traveling on a plane, going long distances, on occasion get up and walk around. Or squeeze the muscles in your legs and get the blood moving."
The American Heart Association reports that moving around, drinking water and avoiding alcohol may help minimize the risk of developing blood clots after long flights. Wearing compression stockings, which squeeze leg muscles and help return blood flow from the legs to the heart, and taking regular baby aspirin to thin the blood, may also help reduce the risk; but talk to your doctor first.
"Blood clots are usually provoked by trauma to a leg, after [hip or knee replacement] surgery, sitting around and the blood cooling or a clot abnormality," explains Dr. Dauterman. Those with a history of cardiovascular disease, stroke or previous blood clots are at greater risk of deep vein thrombosis according to the American Heart Association. Other risk factors include pregnancy, cancer, diabetes, smoking, increasing age and obesity.
The blood clots of deep vein thrombosis are less common than the fatty plaque deposits of peripheral vascular disease.
"Peripheral vascular disease is basically clogged arteries due to atherosclerosis or plaque build up. It's generally slow blockages of the arteries that occurs over time," says Dr. Mark Eaton, a cardiologist with Oregon Surgical Specialists in Medford. Sudden blockages can also occur when a piece of plaque breaks off and obstructs the flow of arterial blood or a blood clot forms in the clogged artery in response to inflammation.
People with peripheral vascular disease may have trouble walking because of poor blood flow in their legs and feet. "It's usually crampy type muscle pain that they feel in the calf muscles or the thigh muscles, sometimes in the buttocks," Dr. Eaton notes. "They've got enough blood to stand there but when they try to walk, their muscles need more blood but they can't get it and so they get crampy muscle pain."
Dr. Eaton ticks off the symptoms of peripheral vascular disease: "The toenails become hypertrophic or kind of clumped up on themselves. You see hair loss on the legs. You see rubor, where the feet kind of turn red," he says. "On physical exam you see diminished pulses so when you try to feel the pulse in their feet they don't have a good pulse because it's blocked above it."
Peripheral vascular disease may be a warning sign of coronary heart disease, cautions Dr. Dauterman. "If you do have blockage in one of the smaller arteries [in the legs or the neck for example], you have a 50 percent chance of severe blockage in one of the larger arteries."
A little prevention goes a long way when it comes to peripheral vascular disease.
"A common-sense diet of fruits and vegetables, more turkey and chicken, avoid fried foods, get your exercise and see your doctor on occasion," advises Dr. Dauterman. "The key thing is to find a way to keep your arteries healthy. Poorly controlled diabetes, high blood pressure, poor diet and inactivity make a great recipe for cooking up blocked arteries."
And Dr. Eaton suggests, "Best thing is good health, stay thin, don't smoke, eat right, exercise and everyone over the age of 50 should take an baby aspirin once a day, male and female. Definitely, without a doubt."
However, it's always best to check with your own doctor before starting any new medicine.