Sciatic nerve, wow does it ever hurt
The pain in the usually come from a disc being out of line, I had it, I went to a chiropractor, it took a while for them to get me back where I was suppose to be but it did get better, after I got better I started to exercise and stretch. I go back once a month just so I stay in line. If you go to a chiropractor, make sure it is a good one that x-rays you first, because some do not and if they are good and can not fix it they will tell you. Good luck and I hope you feel better.
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WebMD or if you do not want to hunt for it please read
Sciatic Nerve treatments