The sciatic nerve is a large nerve that runs from the lower, or lumbar, spine down the back of each leg. An inflammation of the sciatic nerve may cause sharp pain that shoots down the leg and sometimes into the foot. This condition is called sciatica. It usually occurs on one side. As many as 40 percent of people in the U.S. may experience sciatica at some point in their life.
The following are some of the most common causes of sciatic nerve pain.
Discs are the cushions between the spinal vertebrae that act as shock absorbers for the spine. When discs become injured or wear out with age, the soft gel-like center may push against the outer ring. This causes the disc to bulge, or herniate. It can press on nearby nerves, causing pain. If the outer ring of the disc tears or ruptures, the center portion can leak out and cause additional inflammation. When a disc in the lumbar spine herniates, the result may be sciatic pain. Specific movements may aggravate the condition including bending forward, lifting heavy objects, sitting for long periods, and coughing or sneezing.
Spinal stenosis is a narrowing of the spaces within the spine. Most cases are due to aging and wear and tear on the spine. This narrowing compresses the adjacent nerves or the spinal cord itself. When stenosis occurs in the lumbar spine, the sciatic nerves may become compressed and inflamed.
Bone spurs are growths that often occur as individuals age. They may be the result of osteoarthritis, joint degeneration, injury, or heredity. Bone spurs can be a problem if they develop in the openings for nerve roots. Bone spurs in the lumbar spine may put pressure on the sciatic nerve.
Injury or Trauma
Sciatica may be the result of an injury or trauma to the sciatic nerve. Trauma suffered in a vehicle accident, from a contact sport, or from a fall can cause damage and inflammation to the nerve. Fragments of bone from a fracture can also cause damage.
Spinal tumors are abnormal growths that may be cancerous or benign. Either type can compress the sciatic nerve when they occur in the lumbar spine. Spinal tumors are rare.
Symptoms of Sciatica
- Pain in the low back
- Constant pain on one side of the buttocks
- Hip pain on one side
- Pain, burning, and tingling in the back of the leg
- Weakness or numbness in the leg or foot
- Pain that becomes worse after sitting
Risk Factors for Sciatica
- Age – contributes to discs degenerating and wearing out
- Obesity – puts extra pressure on the discs
- Occupation – strenuous, physical jobs that require lifting, twisting, and moving
- Certain activities – contact sports including football and basketball; weight lifting