Nerves are extensions from the brain and spinal cord that reach out into the body. A nerve cell located in the brain or within the spinal cord is called a central nerve. A nerve that extends from the spine into the arms or legs is called a peripheral nerve. Peripheral nerves are actually bundles of millions of nerve fibers that branch from the spinal cord and target muscles to make them move or skin to provide feeling.
A nerve can be pinched as it leaves the spine by a herniated disc or by bone spurs formed from spinal arthritis. Nerves anywhere in the body may be pinched or pressed by a ligament or a tendon and a bone.
With a pinched nerve in the lower back, pain is usually felt radiating down the leg. This pain travels the length of the nerve.
Painful muscle spasms in the back often occur with pinched nerves. Sometimes, the only symptoms may be numbness and weakness in an arm or leg without any pain.
Causes and Risk Factors
A pinched nerve usually occurs when a nerve is squeezed (compressed) by a ligament or tendon, or between a bone and a ligament or tendon. Various spinal conditions, such as a herniated disc or arthritis, can create rough spots in the bone through which a nerve root passes. Overuse, as in carpal tunnel syndrome, can cause a pinched nerve.
To diagnose a pinched nerve, a doctor will take the patient's medical history and perform a physical examination. Imaging procedures (such as X-rays, computed tomography (CT) scans, and magnetic resonance imaging) may be helpful in defining the nature of the compression on the nerve.
Treatment will vary with the specific causes and location of the pinched nerve. Options include:
- Pain-relieving drugs
- Physical therapy
- Cortisone injections
The main goal is to give the nerve root the room it needs. This is done by shrinking the swollen tissue around the nerve, removing scar tissue that may have built up around the nerve from chronic swelling and tenderness or by removing the disc or bone spurs that are pressing on the nerve.