The lower back is a hub for many nerves, including sciatic nerves, the largest nerves in the body. Two sciatic nerves -- each as big around as a finger -- run from the bottom of the spine, through the buttocks, and down each leg. If anything presses against one of the nerves, you will feel the pain of sciatica.
Sciatica comes in many different guises. Some people experience a mild pins-and-needles sensation running down their leg, while others feel a sharp, shooting pain. The pain may be mainly limited to the legs, or it can start in the back and run all the way to the toes. A severely compressed nerve can cause weakness and numbness in the leg. The good news is that sciatica rarely lasts. According to a report from the American Academy of Orthopaedic Surgeons, 80 to 90 percent of people with sciatica eventually recover without having to resort to surgery.
What causes sciatica?
Many people with sciatica have a herniated disk in their lower back. Disks are flexible cushions with a jelly-like center that fit in between vertebrae and help absorb shocks. With advancing age or excessive strain, the cushions can wear thin. Eventually, the jelly-like center of one or more disks can start to ooze out. This is called a herniated, ruptured, or "slipped" disk. In some cases, the center can spread out and press against a sciatic nerve, causing sciatica.
Arthritis in the back may cause extra bone to grow along the spine and is another possible cause of sciatica. So, more rarely, is a sprained ligament in the back, which swells up and presses against the sciatic nerve. Other unusual causes include abscesses or blood clots in the back. Sometimes the culprit is something outside of the body that's pressing against a nerve. To take the classic example, a truck driver who has a fat wallet stuffed in his back pocket may feel sciatica after many miles.
What can I do about sciatica?
Most cases of sciatica go away on their own. You can speed the healing process by taking good care of your back. You may need to take it easy for a few days. Don't lift heavy objects, bend repeatedly, sit for long periods, or do anything else that might aggravate your back. But you don't want to become inert, either. Regular activity will help strengthen your back and promote healing. Your doctor or physical therapist can recommend specific exercises to speed the healing process and prevent future injuries.
While you're waiting for your back to heal, over-the-counter pain relievers such as aspirin or ibuprofen may be helpful. You may want to consult your doctor for the appropriate dose and frequency to achieve safe, maximal relief from your pain. Initially, for extra relief, try putting an ice pack on the sore area for 20 minutes at a time, four times a day. After 48 hours, apply heat to the area where you feel pain and, should the pain continue, try alternating with hot and cold packs. If your back continues to hurt, your doctor may prescribe stronger painkillers. Injections of corticosteroids -- medicines that calm inflammation -- are another option for pain control. Stretching and exercises and physical therapy may also help in many cases.
Some new treatments are being explored, including radiofrequency discal procedures, which help remove up to 20 percent of the nucleus of the disc to relieve pressure on it; however, some evidence suggests this can hasten disc degeneration. Others use spinal pumps for targeted delivery of pain medication.
When is surgery necessary?
For a small number of people with herniated disks, surgery may be the best way to cure sciatica. If signs of nerve damage -- numbness, tingling, and weakness -- grow steadily worse, your doctor may recommend surgery to remove the part of the disk that's pressing against the sciatic nerve. A herniated disk that interferes with bowel and bladder function also requires immediate treatment. For other patients, doctors take a wait-and-see approach.
If your sciatica lingers for six weeks or more despite your self-care efforts, you and your doctor may need to start thinking about surgery. In cases where the pain is not getting better, or where there is persistent numbness or weakness, surgery is often considered. In these cases, an MRI will be needed to determine whether your symptoms are amenable to surgery.
Although it's hard to be patient when you're in pain and have difficulty getting around, time can be one of the best therapies for sciatica. With a little rest, gentle exercise, and some help from your doctor, you should be up and about before too long.
Johns Hopkins White Paper on Back Pain and Osteoporosis.
Richeimer, S, MD. New Technologies for Treating Sciatica and Back Pain. Spine Universe. https://www.spineuniverse.com/conditions/sciatica/new-technologies-treating-sciatica-back-pain
Mayo Clinic. Sciatica.
Mayo Clinic. Spinal Stenosis: Causes. March 2008.
Mayo Clinic. Herniated disks.
American Academy of Orthopaedic Surgeons. Sciatica.
American Academy of Orthopaedic Surgeons. Herniated disk.
Deyo RA and JN Weinstein. Primary care: Low back pain. New England Journal of Medicine 344 (5) 363-370.