Well, it appears I've finally found out what's wrong with my foot. The GP in the UK seems to have given me the absolute basics but it might have been nice if she'd told me the long-term news. Instead of which, I have to get my info from Google.
Using a phrase that the GP mentioned while I was there, I've done some research. And I can confidently say that I have PTS - Post Thrombotic Syndrome. Every single thing I found on the net today fits perfectly. Thanks to the multiple blood clots on my lungs that I had in 2003, which it seems came from an undiagnosed DVT in my calf, I am now joining the high percentage of post-DVT PTS sufferers. Ah, so many acronyms!
There are 2 annoying things : 1) it appears that my chances of getting it COULD have been lowered if I'd been given certain advice/treatment immediately after my 6 months on blood thinners following the pulmonary embolii and 2) there is now nothing that can be done for it and I can look forward to years of foot/leg pain, swelling, discolouration and if I'm really lucky in the end, open ulcers. Referred to on most websites as leading to chronic morbidity.
Oh goody. Bit pissed off, frankly.