+1 more for back problems. Pulled or pinched something one time, I dunno what I did, but the pain was awful and I couldn't move. Collapsed into a chair and basically froze up. if I tried to get up, it was so bad I nearly passed out. The squad came and got me, and few hours later I was able to walk (barely) out of the ER. It hurt for a few days afterwards. Still have various issues/soreness pretty often.
Another time I slipped on ice, fell and landed funny, and partially tore the MCL in my knee. Got up and quickly hobbled into my truck in extreme pain thinking it was a really bad sprain, until I got in my truck and pretty much went into shock. Passed out for a minute, then managed to start the truck and crank the air conditioning to full blast (even though it was below freezing outside) because my face felt like it was on fire. My body was numb for about 15 minutes, I could barely move my fingers or open my mouth. It took a long time to heal, which was pretty annoying.
I used to occasionally get migraines when I was younger that were so bad, I'd start shivering and puking. FUCK migraines.