So, in the interest of raising my word count for the day, have a post.
Please note: this post describes a medical situation that turned out not to be the emergency I thought it might have been; I'm ok and, as it turns out, was never in any danger. However, if you have problems reading about medical emergencies, scary symptoms, hospitals, or needles you will probably be best off with the cut text.( tl;dr: I'm ok. Nothing to worry about. )
Lab work, EKGs, and X-rays all looking perfectly normal, around 3:30 am they gave me my discharge paperwork, and I called G for a ride home. He was sleepy; N came instead. Have I mentioned recently how awesome my sister is? She's awesome.
Note that at this point most of the pain had gone away, but there was still a little achiness around my right shoulder, and the second joint of my right index finger was still almost as painful as it had been at the start. It still is, over 12 hours later.
On the way home N, who is a professional massage therapist, said that it sounded like a pinched nerve was the most likely explanation. Specifically, something called thoracic outlet syndrome. Which is sort of like carpal tunnel syndrome, only between your collarbone and your first rib.
When we got home, I put a sick day on my work calendar -- if I go to the ER in the middle of the night I've damned well earned a sick day no matter how much better I feel in the morning.
So here's what Wikipedia says about it: "Pain can be present on an intermittent or permanent basis. It can be sharp/stabbing, burning, or aching. TOS can involve only part of the hand (as in the 4th and 5th finger only), all of the hand, or [...] the pectoral area below the clavicle, [...] and the upper back (i.e., the trapezius and rhomboid area)." Um... right. What they said.
"The two groups of people most likely to develop TOS are [...] and those who use computers in non-ergonomic postures for extended periods of time. TOS is frequently a repetitive stress injury (RSI) caused by certain types of work environments." ... and I noticed, as I sat there at my desk with my right hand on the trackball, that my right shoulder was uncomfortably higher than my left one.
My desk at home, which consists of a sheet of plywood resting on a 2-drawer filing cabinet and a couple of 2x2 legs, is about 3" (7.5cm) higher than it needs to be. That would probably do it.
... so it looks like I need to take everything off my (cluttered) desk, disassemble the thing, make shorter legs for it, and put everything back. Grumble.