Yep, I should add in that flights are a very common catalyst for DVTs.  So common that they often call it &quot;economy class syndrome&quot; (<a href="http:&#x2F;&#x2F;www.medicinenet.com&#x2F;script&#x2F;main&#x2F;art.asp?articlekey=15872" rel="nofollow">http:&#x2F;&#x2F;www.medicinenet.com&#x2F;script&#x2F;main&#x2F;art.asp?articlekey=15...</a>) - my clot was possibly catalyzed by a flight but that is not yet conclusive.  Needless to say, try to move around as much as possible on a flight (even it means wiggling your toes or legs), and stay healthy (you are much more likely to get a DVT from a flight if you are already unhealthy).