Sciatica is nerve pain arising from the sciatic nerve. It can be produced by pressure on the nerve, where it passes through the buttock. Sciatica can be brought on by sitting on a hard seat. When your leg goes to sleep, that is also a form of sciatica.
The sciatic nerve is a large nerve, formed from nerve roots that originate from the spinal cord. These nerve roots pass out between the disc spaces and join up to form the sciatic nerve. It passes from the spine into the buttock, then into the back of the thigh and leg.
The sciatic nerve controls sensation and function to the leg and foot. In sciatica, prolapsed or 'slipped' discs tend to bulge and press on the intervertebral nerve(s). This pressure irritates the nerve, causing referred pain.
Most cases of sciatica resolve by themselves within six weeks to three months.
Sciatica can also be caused by narrowing of the nerve tunnel between discs due to osteoarthritis. Elderly people who suffer from disk degeneration as a consequence of ageing tend to be troubled the most by sciatica.
