I had a couple sessions when I was younger, back in my 20's. I went a few times under this one place's introductory program. That's when I found out that I broke my neck about a year and a half earlier.
I'm burying the lede a little, but around April 2001 I had an accident involving a dog, a flight of steps, flying through the air, and landing very hard on the street below. It was kind of a sucky week. I had a severe concussion, cervical contusions, and they mentioned one or two other things at the hospital but to be honest I had a hard time remembering that week down the road. The only reason I remember it now was I spent so much time focusing on things they became baked into the long-term memory. Fast forward a year or so and I have constant neck pain. Like, I went from being a heavy headbanger to I couldn't look up for more than 10 seconds at a time. At the chiropractor they take a couple x-rays, and the first question he asked when he came in the room. "So, when did you break your neck?"
At least knowing how bad things were helped me going forward with dealing on how to proceed with life. I stopped going to the chiropractor because I'm a yank and had no insurance and each session cost more than rent.