Feeling pain as adrenaline fades

[clover_elf_kin]

I don't even know where to begin looking for this, and I suspect this isn't something most articles would cover anyway. I know adrenaline serves as a pain blocker during, say, the rush of battle (my attempt at Googling clarified why, at least), but when the adrenaline starts to fade, how does it feel? Does the pain hit you all at once, or you become aware of it gradually?

While I'm asking, might as well confirm a guess: when you wake up in pain (after you've been knocked cold from whatever caused it), is the pain generally the first thing you become aware of? I seem to recall reading this in a book or two, but confirmation (or denial) would be nice.

Thanks in advance!

~yet another NaNo writer behind schedule