I'm tagging this post with 'Mozilla' because many Mozilla people travel a lot.
In September, while in California for a week, I developed pain in my right calf. For a few days I thought it was a muscle niggle but after I got back to New Zealand it kept getting worse and my leg was swelling, so I went to my doctor, who diagnosed a blood clot. A scan confirmed that I had one but it was small and non-threatening. I went to a hospital, got a shot of the anticoagulant clexane to stop the clot growing, and then went home. The next day I was put on a schedule of regular rivaroxaban, an oral anticoagulant. Symptoms abated over the next few days and I haven't had a problem since. No side-effects either. I cut myself shaving at the Mozilla Summit and bled for hours, but that's more of an intended effect than a side effect :-).
I had heard of the dreaded DVT, but have never known anyone with it until now, and apparently the same is true for my friends. Fortunately I didn't have a full-blown DVT since the clot did not reach a "deep vein". Still, I can confirm these clots are real and some of the warnings about them are worth paying attention to :-).
I saw a specialist for a followup visit today. Apparently plane travel is not actually such a high risk so in my case it was probably just a contributing factor, along with other factors such as sitting around too much in my hotel room, possibly genetic factors, and probably some bad luck. (Being generally healthy is no sure protection; ironically, I got this clot when I'm fitter than ever before.) So when flying, getting up to walk around, wiggling your toes, and keeping fluid intake up are all worth doing. I used to do none of them :-).
My long term prognosis is completely fine as long as I take the above precautions, wear compressing socks on flights and take anticoagulant before flights. I will be given a blood test to screen for known genetic factors.
I did everything through the public health system and it worked very well. Like health systems everywhere, New Zealand's has its good and bad points, but overall I think it's good. At least it doesn't have the obvious flaws of the USA's system (the only other one I've used). In this case I had basically zero paperwork (signed a couple of forms that staff filled out), personal costs of about $20 (standard GP consultation), good care, reasonable wait times, and modern drugs. I was pleased to see sensible things being done to deliver care efficiently; for example, my treatment program was determined by a specialist nurse, who checked it out with a doctor over the phone. New Zealand has a central drug-buying agency, Pharmac, which is a great system for getting good deals from drug companies (which is why they keep trying to undermine it, via TPP most recently ... of course they managed to make the Pharmac approach illegal in the USA :-(.) Rivaroxaban is relatively new and not yet funded by Pharmac, but Bayer has been basically giving it away to try to encourage Pharmac to fund it.
Overall, blood clots can be nasty but I got off easy. Thanks God!