# Flying and blood clots **URL:** \ **Category:** Factual Questions\ **Created:** [August 13, 2008, 2:08am UTC](https://boards.straightdope.com/t/flying-and-blood-clots/459803 "2008-08-13T02:08:38Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [August 13, 2008, 2:08am UTC](https://boards.straightdope.com/t/flying-and-blood-clots/459803/1 "2008-08-13T02:08:38Z")
I know frequent travellers are warned about potential blood clots, especially in the legs. Is this simply because they spend a lot of time not moving, or does the environment of an airplane make blood clots more dangerous? I ask because I have something weird going on with my leg - I get very severe bruising and some swelling. I saw a doctor and had an ultrasound done and they ruled out DVT, but I’m not sure they did their job properly. It’s been going on and off for months though so maybe it’s something else. So anyway, I was on my feet a lot today and I have a huge dark bruise on the back of my calf to show for it. I’m flying in 2 days. Am I in any abnormal danger? Or does the risk of blood clots to travelers come entirely from moving infrequently? I could counteract that by walking every hour or so. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [August 13, 2008, 2:21am UTC](https://boards.straightdope.com/t/flying-and-blood-clots/459803/2 "2008-08-13T02:21:07Z")
First, IANAD There are two problems with the flying and the blood clots. The first, as you indicated, is a problem of not moving around enough. You have also come up with a remedy for that. You can also do things like flex your feet and shift position while sitting. The second problem has to do with being in thinner, drier air. Thin dry air can affect how fast you dehydrate which (if my information is correct) can also make these problems more likely. Therefore, maintaining adequate fluid intake (which might also prompt you to get up for often because you need to pee occasionally) would also be a good idea. However, if a trained medical professional contradicts anything I’ve said please take their word over mine. ---
**Author:** ![conurepete](https://avatars.discourse-cdn.com/v4/letter/c/a88e57/32.png) [@conurepete](https://boards.straightdope.com/u/conurepete)\ **Post date:** [August 13, 2008, 3:11am UTC](https://boards.straightdope.com/t/flying-and-blood-clots/459803/3 "2008-08-13T03:11:19Z")
I would really, really want to know why the bruising. It’s not normal. What is leaking and why? Even if it is just a little tear in the gastrocnemius muscle leading to colorful bruises, you would feel better knowing what is going on. Body parts are not supposed to randomly leak blood. ---
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [August 13, 2008, 3:24am UTC](https://boards.straightdope.com/t/flying-and-blood-clots/459803/4 "2008-08-13T03:24:12Z")
Yeah, I would like to know it too. Unfortunately the doctors I’ve seen have been… uninterested in helping me, and I have limited medical means. I’ve sort of put it on the back burner because it’s one of the least troubling of my symptoms. But the re-emergence of the bruise and the proximity of my flight has me a bit scared. ---
**Author:** ![LiveOnAPlane](https://avatars.discourse-cdn.com/v4/letter/l/3d9bf3/32.png) [@LiveOnAPlane](https://boards.straightdope.com/u/LiveOnAPlane)\ **Post date:** [August 13, 2008, 4:41am UTC](https://boards.straightdope.com/t/flying-and-blood-clots/459803/5 "2008-08-13T04:41:02Z")
I don’tfeel qualified to answer your posted question, but I will offer some advice if you absolutely, positively have to fly off. Make sure you have a list of walk-in clinics close by your work site. It’s a real bitch hving a medical problem crop up and you do’t where to go and aren’t in shape to ask the locals at work who they’d recommend. I say this hoping that nothing happens, and if something does, it is not severe enough for an ambulance ride to the ER. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [August 13, 2008, 10:13am UTC](https://boards.straightdope.com/t/flying-and-blood-clots/459803/6 "2008-08-13T10:13:13Z")
Not totally on-topic, but “flying” _per se_ is not associated with clots. Rather, _lengthy_ flights are. By ‘lengthy’, the literature would suggest flights around the 12 hour mark (!), e.g. from North America to Australia or the UK to South Africa. There is little or no risk in, say, flying from New York to Chicago. Other forms of transportation are not immune from this. People on long car trips, where they may be cramped and unable to stretch their legs can also develop clots. As mentioned, though, flying does add another risk, i.e. dehydration.