Updated December 19, 2014.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

The diagnosis of sciatica means that there is irritation of the sciatic nerve. The sciatic nerve transfers information to and from your brain. The brain sends messages to the muscles, and the nerve transmits signals back about pain and sensations. The sciatic nerve is quite large, in fact, it is the largest peripheral nerve in the body.

The sciatic nerve is formed from the lower segments of the spinal cord; it is made up from the lumbar and sacral nerve roots from the spine.

The sciatic nerve exits the lower part of the spinal cord, passes behind the hip joint, and runs down the back of the thigh.

The sciatic nerve, like most other nerves, performs two basic functions: first, it sends signals to your muscles from the brain; and second, it collects sensory information from the legs and passes this back to your brain. Conditions such as sciatica that affect the nerve will alter these normal functions. The usual symptoms of sciatica include:

• Electric shock pain down the leg
• Numbness & tingling sensations
• Muscle weakness

In addition, patients with sciatica may notice a worsening of their symptoms with maneuvers such as squatting or coughing. These maneuvers can increase pressure around the nerve and magnify the symptoms of sciatica.

Causes of Sciatica

The most common cause of sciatica is a herniated spinal disc. When this happens, the normal cushion between the vertebra of your spine ruptures. This causes the disc to push out into areas normally occupied by these nerves.

The nerves are compressed and people then experience the symptoms of pain, weakness, and numbness. Other conditions, such as spinal stenosis, spondylolisthesis, or piriformis syndrome can also cause cause sciatica symptoms by irritating the sciatic nerve.

Sciatica can affect just about anyone, but it is extremely uncommon in children and adolescents patients. Sciatica typically affects 30 to 50 year old patients. Often there is a sudden onset that may be attributed to over-exertion or a back injury.

Treatment of Sciatica

In order to properly treat the symptoms of sciatica, you need to find out the cause of the problem. Your doctor will take a thorough history, perform a physical exam, and test several specific functions of the sciatic nerve. Several other conditions may cause hip and thigh pain, and need to be considered. It is important to determine the correct cause of your symptoms prior to beginning treatment of sciatica. Other tests, including x-rays or possibly an MRI may be helpful, but they may not needed.

Treatment is initially aimed at addressing the inflammation associated with sciatica. Rest, anti-inflammatory medications (such as Motrin or Celebrex), and muscle relaxers are often good places to start. Some patients require a more powerful anti-inflammatory treatment and are given oral steroid medications. These steroids do have potential side-effects, but the powerful anti-inflammatory effect can be helpful in the treatment of sciatica.

Once the pain subsides, exercises and physical therapy are helpful. Many people find that heat packs and ice packs soothe the muscles that are painful in sciatica. Some doctors may prescribe an epidural steroid injection that can deliver anti-inflammatory medication directly to the inflamed area around the nerves.

Surgical treatment of sciatica is not usually needed, but in individuals who undergo the above treatments, and have persistent symptoms, surgery may be considered. The surgical procedure is one that allows more room for the nerve in the area being compressed. This may mean removing the ruptured disc, opening up the bone around the nerve, or a combination of both.

Most people (80-90%) fully recover from sciatica without surgery. In most cases the nerve is not permanently damaged, and individuals recover in the 3-week to 3-month time frame.