Did you know that it may matter for your health whether you choose an aisle or a window seat on long flights? It can actually be more dangerous for you to sit in the window seat. This has nothing to do with the window itself, space radiation or temperature which might be the first things that pop to your mind.
During long flights blood clots may develop in the deep veins of the limb, a phenomenon known as DVT (deep vein thrombosis). It has been proposed that the risk of DVT may be related to less space on flights and therefore this phenomenon has commonly been nicknamed "economy class syndrome". These blood clots me be hazardous as they can float to the lungs and get stuck in their arteries (pulmonary embolism).
Sitting in a window seat is a risk factor for DVT, the American College of Chest Physicians (ACCP) warn in their new advisory, regardless of whether it's in economy or first class.
Various risk factors for blood clots in deep veins during flight have been identified. Immobility seems to the biggest risk factor. If you sit in a window seat you are more unlikely to stand up and move around than if you you sit by the aisle. If you sit in the aisle seat you can stand up whenever you like without annoying anyone. If you sit by the window, the person next you you might be in the middle of meal or in deep sleep when are going to do your hourly leg exercise, so you will probably skip it.
"DVT risk has nothing to do with economy class," said Dr. Gordon H. Guyatt, chair of the ACCP panel that drafted the new guidelines. "Really, the evidence is that actually where you sit isn't really an issue. It's how much you move around. And if you're in a window seat you are probably more willing to sit for long periods of time being uncomfortable because you are reluctant to make anybody else move to let you out." These instructions are published in the latest issue of the journal Chest, and you can view them here.
Still, "the first thing to say is that if you are a healthy person you should not really worry about DVT because your risk -- even on a long-term flight -- is considerably less than one in a thousand," said Guyatt, who is also professor in the department of clinical epidemiology and biostatistics at McMaster University in Hamilton, Ontario, Canada. "So these guidelines are for those who have more than a normal risk. For those who have had a clot before, or an abnormality of their coagulation system, or disability that affects mobility. Or if you are obese or have active cancer." Others who are at risk are older people, pregnant women, women who take estrogen replacement therapy, such as oral contraceptives and individuals who have recently undergone surgery.
Apart from seating considerations, the guidelines also suggest that people on flights lasting six or more hours move about frequently and stretch their calf muscles.
Higher-risk individuals should also wear graduated compression stockings that stretch below the knee. Guyatt said it "would be crazy" for passengers at normal risk to wear such stockings, and the ACCP guidelines specifically argue against their use by healthy passengers.
The guidelines also generally discourage the taking of aspirin and/or anticoagulant medications for the specific intent of lowering DVT risk. That said, those at very high risk are encouraged to consult their doctors in order to weigh the pros and cons of such drugs. Obviously it is not advisable to take a sleeping pill and curl up in your seat for the whole voyage.