This question relates to back pain and sympathetic nervous system response. I was installing some new lights in my boat a few days ago when i felt something shift or pop in my lower back and a managable pain immediately followed the incident. I stood up and tried to stretch it out to no avail so i continued to do what i was doing. About an hour later i was in my kitchen leaning on the counter trying to stretch the affected area in the lower back again when all of a sudden debilitating and intense pain started pretty much in the center of my lower back. It brought me to my knees and i had a hard time standing back up. I managed to take a few pain pills, put some icy hot on, and iced my back good and went to bed. I had a pretty good nights sleep despite the pain when i would move around. When i tried getting out of bed the next morning i had a hard time standing up because of the pain. I stood up for a brief second but immediately was sent to my knees again due to the pain. I crawled across the floor so i could get to the bathroom when all of a sudden the strangest sensation came over my whole body. I felt a warm feeling in my lower back followed perfuse cold sweating all over my body. I was confused, short of breath, tachycardic, and didnt know where i was at for a brief second. I had a tingling sensation throughout my body, i was very light headed and i was nauseated. I continued to crawl to the bathroom and i sat on the toilet. All of a sudden, my back pain completely vanished. I continued to have the perfuse cold sweats, tachycardia, shortness of breath, tingling, and nausea for a few minutes until that finally went away to. This happened two days ago and i am still pain free. How can you go from having the most excrutiating pain you have ever experienced in your life to having none at all so quickly? What was up with sympathetic nervous system response that i experienced the moment the pain went away?