Ah, well, you need to look in the right places - either my status messages or
potsy's 'GWS ColinJ' thread!
I did a 100 km hilly forum ride to Otley on the 15th July. By the 19th July I was starting to have breathing problems. On the 22nd, I was gasping for breath at the very start of the Cragg Vale climb. It just got worse and worse before I finally realised that this was not some chest infection that I'd get over in the usual fashion. I went for a chest x-ray in Todmorden and my left leg was swelling up and going purple on the way home, so I went straight to the GP who suspected what I feared - a DVT - and sent for an ambulance!
Short version - a pretty serious health problem (DVT/pulmonary embolism) which is responding well to Warfarin treatment!
I'm probably off my bike for the rest of this year, but aim to be doing as much walking as possible to get my legs working again.