Sciatica is defined as the sensation of pain, tingling and/or numbness in the back, buttocks and/or legs produced by an irritation of the sciatic nerve.
The sciatic nerve is made up of multiple nerves as they exit from the spinal cord and enter the lower portion of the back. The sciatic nerve also extends through the buttocks and down the back of each leg to the foot and ankle.
The most common causes of sciatica are herniated, bulging or degenerative discs which cause pressure and irritation to the nerve. Other causes may include small bony growths on the spine (bone spurs) and the compression or pinching of the nerve by the muscles of the buttocks or leg. And in some cases, sciatica may be caused by tumors, pregnancy and spinal stenosis.