Sciatica is a general term that refers to pain in the leg. Numbness, weakness or tingling may occur with pain. The sciatic nerve runs down the back of the thigh and it has as components several nerves from the spine. Consequently, sciatica can be pressure on a nerve in the spine (common) or less, commonly, injury to or compression of the sciatic nerve.
Causes, incidence, and risk factors
Common causes of sciatica include:
- Herniated lumbar disca with pressure on a spinal nerve
- Degenerative disc disease which causes pressure on spinal nerves
- Spinal stenosis
- Pelvic injury or fracture
- Rarely, tumors
The symptoms of sciatica can vary but typically pain from the buttock down the posterior thigh occurs which can travel to the calf. Numbness, tingling or weakness may accompany it. It may vary with position, time of day, with activity or posture. Back pain may be associated with it.
Signs and tests
Physical examination may reveal numbness or weakness when assessed by a spinal physician. There may be reflex changes and pain on lifting the leg (the so-called "positive straight leg raise')
Follow up studies such as xrays, MR scans and nerve studies may be ordered.
Sciatica is not a disease, it is a symptoms. Therefore treatment of the underlying condition, such as spinal stenosis or acute disc herniation may address the sciatica. Typically this involves conservative therapy such rest, NSAIDs, and physical therapy. See Good Back Care for more information.
Surgery is occasionally done:
see lumbar microdiscectomy or lumbar laminectomy
Depending on the cause and duration of symptoms the prognosis is varied, but most patients can get good relief.
Calling your health care provider
- Unexplained fever with back pain
- Back pain after a severe blow or fall
- Redness or swelling on the back or spine
- Pain traveling down your legs below the knee
- Weakness or numbness in your buttocks, thigh, leg, or pelvis
- Burning with urination or blood in your urine
- Pain that is worse when you lie down, or awakens you at night
- Severe pain and you cannot get comfortable
- Loss of control of urine or stool (incontinence)
Also call if:
- You have been losing weight unintentionally
- You use steroids or intravenous drugs
- You have had back pain before but this episode is different and feels worse
- This episode of back pain has lasted longer than 4 weeks
If any of these symptoms are present, your doctor will carefully check for any sign of infection (such as meningitis, abscess, or urinary tract infection), ruptured disk, spinal stenosis, hernia, cancer, kidney stone, twisted testicle, or other serious problem.
Prevention varies depending on the cause of the nerve damage. Avoid prolonged sitting or lying with pressure on the buttocks. Good Back Care is essential.