The illustration here shows the center point of sciatic (or sciatica) nerve pain.

© Sebastian Kaulitzki | Dreamstime.com

The sciatic nerve is the biggest single nerve in the body, and has many sections that branch out through the lower spine area and down your legs. If any part of the sciatic nerve is squeezed or pinched, the result of this compression is searing pain in your lower back that travels on down through the buttock and leg, even as far as your foot.

You also may experience tingling or numbness.

You’re more at risk for sciatic nerve pain if you’re older, obese, and/or if you work in an occupation that requires a lot of bending and twisting of the spine or, conversely, a sedentary position. Diabetes also can raise your risk, since it can damage your nerves. (For information on easing sciatica pain, see our post “Solutions to Soothe Sciatica: Relief May Be on Its Way.”)

What Causes Sciatic Nerve Pain?

Sciatic nerve pain involves some type of nerve irritation that has its origin in the lower back or lumbar spine. Common underlying triggers include:

• A herniated spinal disk: The spinal disks that form a shock-absorbing cushion between the spinal vertebrae can break down as you age (a condition called degenerative disk disease). If this happens, one or more disks may develop tiny cracks that can bulge, rupture, or break—a condition called herniated disk. If a bulging or “slipped” disk pressed on the sciatic nerve, sciatic nerve pain will result.
• Degenerative spondylolisthesis: This condition also is related to wear and tear on the muscles and ligaments of the lower back, which gradually become less able to keep the spinal vertebrae aligned. This makes it possible for one of the vertebrae to slip forward over the vertebra beneath it, pressing on the spinal nerves in the process, and causing sciatica. Many people with degenerative spondylolisthesis find that leaning forward while sitting relieves the pain because it increases the space available for the sciatic nerve.
• Bone spurs: These are bony outgrowths that can develop due to a condition called spinal stenosis. These bony growths—called bone spurs—narrow the space the spinal nerves pass through, eventually pinching the sciatic nerve. As with degenerative spondylolisthesis, sciatic nerve pain related to spinal stenosis symptoms tends to decrease when you sit and lean forward.

Diagnosing Sciatica

It isn’t always necessary to know what’s causing sciatica in order to treat it. However, if your sciatic nerve pain is so severe that it interferes with your sleep or ability to work, you should mention it to your doctor. Any change in urination or bowel movements should also be investigated.

Your doctor can distinguish the underlying cause of your sciatica with an x-ray or computed tomography (CT) scan. He or she also may order a test called an electromyogram, which measures how well your nerves are sending electrical signals to your muscles. Rarely, sciatica can occur because the sciatic nerve is being squeezed by a tumor—if your doctor suspects this may be causing your sciatica, you will likely have magnetic resonance imaging (MRI).

The goal of sciatica treatment is to relieve inflammation. This often can be accomplished by taking a nonsteroidal anti-inflammatory drug (NSAID) such as ibuprofen (Advil, Motrin) or naproxen (Aleve, Naprosyn).

However, if you’re already taking medication for one or more other conditions, talk with your doctor before taking a painkiller, even one that’s available over the counter. If you’re taking a blood thinner such as warfarin (Coumadin) for example, an NSAID may be contraindicated.

To alleviate the muscle spasms in the lower back that are often associated with sciatica, your doctor may recommend icing the affected area for 20 minutes several times a day. This can be an effective back spasms treatment, decreasing pain by cooling the muscles and anesthetizing the sciatic nerve. Exercise also helps relieve muscle spasms, but as a precaution, ask your doctor to refer you to a physical therapist who can show you effective exercises that help stretch and relax your muscles without further irritating the sciatic nerve.

About 80 to 90 percent of people with sciatica find that conservative approaches help to resolve the problem over time. However, if a herniated spinal disk or bone spurs are causing your sciatica, you may need surgery.

Originally published in May 2016 and updated.