Long plane flights carry a risk of DVT. It is easy to find advice on preventing DVT by being active:
- CDC says "walk around every 2-3 hours" and mentions that you should do this when traveling by car also. This article also mentions that you are at higher risk of DVT if you have active cancer or are receiving chemotherapy. It recommends compression socks, too.
- Mayo clinic says "If you're traveling a long distance by car, stop every hour or so and walk around. If you're on a plane, stand or walk occasionally."
- WebMD says "If you are traveling by car, stop every hour or so. Get out and walk around for a few minutes. If you are traveling by bus, train, or plane, get out of your seat and walk up and down the aisle every hour or so. "
None of these mention the possibility of sleeping on the plane. Are they suggesting you should not sleep? We all lie down for 8 hours or so every night, and yes, we can toss and turn a little more freely in a real bed, but I find it hard to imagine this advice means "don't sleep, stay awake so you can walk around a lot."
Further, there is a big difference between "every hour" and "every two or three hours" - and that's not counting good old "occasionally". None indicate whether wearing compression socks means it's safer to go for a longer interval between walks.
So, if a person with at least some risk factor for DVT is going on a long (11 hrs) flight, wearing compression socks, in business with a lie-flat bed, is lying flat in that bed and sleeping actually as dangerous as sitting awake in economy? What about a 13 hour flight in economy, still with the socks, is sleeping for part of that flight dangerous? This is normal sleep without the aid of Ambien or even alcohol, and thus there will be tossing and turning.
Why I'm asking: I have those flights in my future and a doctor told me emphatically to get up "every hour" on the plane and walk around. I didn't think to ask about sleep time, and I have no problem getting up once an hour while awake. But this same doctor knows that I drive two to three hours to and from my appointments, and has never said to pull over the car and walk every hour during a drive. Yet DVT isn't related to altitude, just to sitting still. So I feel the "every hour" is probably a little overcareful. But I am interested in what the studies show, and specifically on the matter of sleeping, in business and in economy. I am not asking for a diagnosis or to override my doctor's advice. I just want to sanity check it since we didn't discuss economy vs business and lying down to sleep. A study showing the effects of following various advice regimens (and that includes overnight flights where people slept or stayed awake) would be great.