Definition

The sciatic nerve begins from the lower spine on either side. It travels deep in the pelvis to the lower buttocks. From there, it passes along the back of each upper leg and divides at the knee into branches that go to the feet. Sciatica is an irritation of the sciatic nerve.

Causes

Sciatica is caused by irritation or pressure on the sciatic nerve. This can be the result of:

• Herniated disk —the cushions between the bones of your spine bulge and press on the nerve as it exits the spinal column
• Arthritis in the lower back
• Spinal stenosis —narrowing of the spinal canal in the lumbar area
• Spondylolisthesis —slippage of a bone in the lower back
• Cauda equina syndrome —nerve roots at the base of the spinal cord are compressed
• Piriformis syndrome— spasm of piriformis muscle

Risk Factors

Sciatica is more common in men. Other factors that may increase your chance of sciatica include:

Lifestyle and personal health factors, such as:

• Obesity
• Smoking
• History of low back problems
• Anxiety and depression

Occupational factors, such as:

• Heavy manual labor
• Heavy lifting
• Exposure to vibrations
• A job that requires standing for long periods of time and forward bending

Health conditions, such as:

• Fractures in the back
• Tumors
• Infections
• Metabolic problems, such as diabetes

Symptoms

Sciatica causes symptoms that can range from mild to severe. In general, sciatica may cause:

• Burning, tingling, or a shooting pain down the back of one leg
• Pain in one leg or buttock may get worse with:
  • Sitting
  • Standing up
  • Coughing
  • Sneezing
  • Straining
• Weakness or numbness in a leg or foot

More serious symptoms associated with sciatica that may require immediate medical attention include:

• Continuing weakness in a leg or foot
• Numbness in groin or the buttocks
• Difficulty walking, standing, or moving
• Loss of bowel or bladder control
• Fever, unexplained weight loss, or other signs of illness

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor will pay particular attention to your back, hips, and legs. The physical exam will include tests for strength, flexibility, sensation, and reflexes.

Imaging tests are used to evaluate the affected area:

• X-ray
• MRI scan
• CT scan

Your doctor may also need to test your nerves. This can be done with a nerve conduction study.

Treatment

The goal of treatment is to reduce sciatic nerve irritation.

Treatment options include:

Prevention

Sciatica tends to happen more than one time. To help reduce your chance of sciatica:

• Use proper body movement when playing sports, exercising, or lifting heavy objects.
• Practice good posture to reduce pressure on your spine.
• Begin a safe exercise program with the advice of your doctor.
• If possible, avoid sitting or standing in one position for long periods.
• Consider job retraining if your work requires a lot of heavy lifting or sitting.

Ortho Info—American Academy of Orthopaedic Surgeons http://www.orthoinfo.org

Canadian Orthopaedic Foundation http://www.canorth.org/

Sciatica. American Academy of Orthopaedic Surgeons Ortho Info website. Available at:
http://orthoinfo.aaos.org/topic.cfm?topic=A00351
Updated October 2007. Accessed November 26, 2013.

Sciatica. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated November 22, 2013. Accessed November 26, 2013.

Waddell G, Feder G, Lewis M. Systematic reviews of bed rest and advice to stay active for acute low back pain. Br J Gen Pract. 1997;47:647-652.

6/7/2007 DynaMed’s Systematic Literature Surveillance
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Peul WC, van Houwelingen HC, et al. Surgery versus prolonged conservative treatment for sciatica. N Engl J Med. 2007;356:2245-2256.