Sciatica refers to pain that radiates along the path of the sciatic nerve and its branches. Most people with a sciatic nerve problem will feel pain down to the buttock. Usually it will only affect one extremity of the body. Pain may vary from mild to a sharp stabbing or burning pain.
If the alignment of the spine is incorrect it can cause extra stress on the nerves, which when bad enough can eventually result in symptoms. If the alignment or function is not optimal in the area of the sciatic nerve you can eventually get nerve pressure or damage, which can eventually result in pain along the nerve.
Chiropractors realign the spine in order to improve nervous system function.