Sciatica Health Article

Definition

Sciatica refers to pain, weakness, numbness, or tingling in the leg. It is caused by injury to or compression of the sciatic nerve. Sciatica is a symptom of another medical problem, not a medical condition on its own.

Alternative Names

Neuropathy - sciatic nerve; Sciatic nerve dysfunction

Causes, incidence, and risk factors

Sciatica occurs when there is damage to the sciatic nerve, located in the back of the leg. This nerve controls the muscles of the back of the knee and lower leg and provides sensation to the back of the thigh, part of the lower leg and the sole of the foot. Incomplete damage to the sciatic nerve may appear identical to damage to one of the branches of the sciatic nerve (tibial nerve dysfunction or common peroneal nerve dysfunction).

Common causes of sciatica include:

• Degenerative disc disease
• Pelvic injury or fracture
• Piriformis syndrome (a pain disorder involving the narrow piriformis muscle in the buttocks)
• Slipped disk
• Spinal stenosis
• Tumors

Symptoms

Sciatica pain can vary widely. It may feel like a mild tingling, dull ache, or a burning sensation. In some cases, the pain is severe enough to make a person unable to move.

The pain most often occurs on one side. Some people have sharp pain in one part of the leg or hip and numbness in other parts. The sensations may also be felt on the back of the calf or on the sole of the foot. The affected leg may feel weak.

The pain often starts slowly. Sciatica pain may get worse:

• After standing or sitting
• At night
• When sneezing, coughing, or laughing
• When bending backwards or walking more than a few yards, especially if caused by spinal stenosis

Signs and tests

Sciatica might be revealed by a neuromuscular examination of the legs by a physician. There may be weakness of knee bending or foot movement, or difficulty bending the foot inward or down. Reflexes may be abnormal, with weak or absent ankle-jerk reflex. Pain down the leg can be reproduced by lifting the leg straight up off the examining table.

Tests are guided by the suspected cause of the dysfunction, as suggested by the history, symptoms, and pattern of symptom development. They may include various blood tests, x-rays, MRIs, or other tests and procedures.