How much of a real risk is Deep Vein Thrombosis?

Factual Questions
1

I’ve noticed the past few times I’ve flown that all the in-flight magazines now seem to include a bit about how you should at least stretch out a few times on a long flight, owing to the risk of developing a blood clot in your legs. If I believe the womens’ health magazines that my mother reads, that blood clot will inevitably travel up to your lungs and kill you (provided you don’t die of heart disease, diabetes, a stroke, or some other godawful disease first).

But in reality, without all the hype, how much of a risk is it? I’m flying from Philadelphia to Albuquerque on Friday. That’s two chunks of about 3 hours on a plane, plus time waiting in the airport (direct flight to Albuquerque? Don’t make me laugh). What are the chances that A) my blood will spontaneously clot up in my legs, and B) said clot would cause a real problem?

And for that matter - if a few hours sitting on a plane can cause this, why isn’t it the Office Worker’s Plague? For that matter, why doesn’t it happen all the time to people when they sleep?

2

A friend of mine recently experienced this. The clot actually did reach his lungs, and he did not die, but was hospitalized. It was very serious.

He, however, flies VERY regularly, and is 6’5" or so. YMMV.

3

I can’t speak for Deep Vein Thrombosis specifically, but blood clots in the legs are definitely something you want to avoid. A clot formed in the legs of a friend of mine killed her when it reached her lungs. She had trouble breathing but died on the way to the hospital. She was 21.

4

Not much of a risk. Few flyers develop blood clots, but DVTs and especially pulmonary emboli are very serious if they do develop.

People who are pregnant, elderly, have cancer, have had recent leg trauma or surgery, are in a cast, smoke, have had a previous blood clot, take estrogen (birth control) and are immobile have increased risk. Sitting in a plane for three hours, as you say, is not much different from sitting in an office chair for three hours.