Sciatica refers to a low back pain that originates in the lower back and radiates through the buttock and down the back of each leg. The leg pain often goes through the knee and may also go to the foot. Weakness in the leg muscles and limping can be the sign of sciatica. Typically, sciatica affects only one side of the body. It is different from other forms of low back pain. It is caused by compression of the sciatic nerves in the lumbar spine, which is the largest single nerve in the body. Although low back pain is a common condition that affects as many as 80–90% of people during their lifetime, true Sciatica occurs in only 5% of cases.
Pain that radiates from the lower spine to the buttock and down the back of the leg is the hallmark of sciatica. Symptoms are usually based on the location of the pinched nerve. There are various forms of sciatic pain varying widely from a mild ache to a sharp, burning sensation or excruciating pain much like the feeling when one’s leg “goes to sleep”. Sometimes it can feel like a jolt or electric shock.
The pain can range from slightly annoying to severely unbearable. Some people have pain in one part of the leg and numbness in another part of the same leg. The pain can be worse when you cough or sneeze, and sitting for a long time can aggravate symptoms. Common symptoms of sciatica include:
- Lower back or hip pain
- Burning or tingling pain down the leg
- Weakness and numbness in the leg
- Difficulty moving the leg or foot
- A shooting pain that makes it difficult to stand up or walk
- “Foot drop”: unable to bend the foot upwards at the ankle
Sciatica most commonly occurs when the sciatic nerve becomes pinched, usually by a herniated disk, bone spur on the spine or the narrowing of the spine compressing part of the nerves. These conditions can cause pressure on the nerve, or irritation, resulting in the symptoms of sciatica. In daily life, sciatica can be caused by carrying large wallets or other hard objects in the back pocket of pants, or sitting on a hard surface for a long period of time. Other risk factors of sciatica are as follows:
- Lumbar spinal stenosis. It is a narrowing of the canal that contains the spinal cord. Many people with spinal stenosis have sciatica on both sides of the back.
- Spondylolisthesis. It is a condition in which one backbone has slipped forward or backward over another backbone which can cause pressure on the sciatic nerve.
- Pregnancy. Many women experience sciatica during pregnancy.
- Age. Sciatica can also be caused by age-related changes in the spine, such as osteoarthritis and fractures due to osteoporosis. People in middle ages are at highest risk of developing sciatica. After 50 years old, the possibility declines.
- Obesity. Excess body weight can increase the stress on the spine and thus contribute to the spinal changes and lead to sciatica.
- Diabetes. This condition will affect the way your body uses blood sugar and further increase the risk of nerve damage.
Sciatica is a clinical diagnosis. A doctor will make the diagnosis based on the patient’s medical history, a physical examination and description of the patient’s symptoms. The following diagnostic procedures are used for diagnosis:
It uses invisible electromagnetic energy beams to produce images of bones.
- Magnetic resonance (MR) imaging
It uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. This procedure can help identify herniated discs.
- CT myelogram
It is a diagnostic imaging procedure that provides images of bones and nerve roots.
- Electromyography (EMG)
It is a diagnostic imaging procedure that provides information on the health of muscles and the nerve cells that control them.
Although the pain which is associated with Sciatica can be severe, most patients with slight symptoms can be treated with non-operative treatments in a few weeks. The conservative(non-operative) treatments include:
- Muscle-relaxant medication
- Anti-inflammatory medication
- Heat/ice packs
- Steroid injections
- Physical therapy (such as massage and stretching and strengthening exercises)
However, people who have severe sciatica associated with significant leg weakness or bowel or bladder changes experience progressive numbness or weakness might be in urgent need for surgery.
About 10%-15% of affected patients require surgical procedures to relieve the pain. If sciatica is due to a herniated disc, the surgeon will perform a surgical procedure known as a microdiscectomy. If sciatica is due to lumbar stenosis, the surgeon will perform a laminectomy. In some cases, the surgeon may need to perform a combination of microdiscectomy and laminectomy. The doctor will tailor the treatment to each patient’s overall condition.