What is Sciatica?
The term sciatica refers to a type of radiculopathy, a pinching or compressing of a nerve that occurs in the leg. Sciatica specifically refers to the radiculopathy that occurs when one or more of the nerves that make up the sciatic nerve are irritated or pinched. Sciatica is no different than a pinched nerve anywhere else in your spine but has its own name because it is fairly common. It also occurs in the lumbar spine which is also the most common site of spinal nerve irritation. The term sciatica is used to describe the pain that travels from the sciatic nerve in the lumbar region of your spine into your buttocks. It can also travel through the back of your thighs, and sometimes into your calf and foot.
Causes & Symptoms
Sciatica is typically caused by irritation of the nerve roots that join outside your spine to make up your sciatic nerve. The sciatic nerve branches off from your spinal cord and travels through your hips, buttocks, and down the back of your legs. The most common cause of sciatica is a herniated disc. The intervertebral discs in your spine act as shock absorbers to protect your spine and keep it flexible. If the disc deteriorates due to normal wear and tear or ruptures due to an injury to your spine, some of the contents of the disc may seep out and press against the sciatic nerve root. Other conditions that can cause sciatica are:
- Spinal stenosis - narrowing of your spinal canal, which can put pressure on the nerve
- Spondylolisthesis - displaced vertebrae of your spine, which can pinch the nerve
- Piriformis syndrome - tightening or spasm of the piriformis muscle in your lower spine and upper leg, which can put pressure on the sciatic nerve
- Spinal tumors - tumor on or within your spine can compress the spinal cord and nerve root
- Trauma - an accident, fall or blow to your spine, which can injure the nerve root
You may be at increased risk for sciatica if you are over 40 years of age because that is when the discs in your spine start to wear out. You may also develop sciatica if your job requires a lot of twisting or lifting, or if you have to drive a lot. People who sit for long periods of time are more likely to develop sciatica, as are people with diabetes because high blood sugar can increase the risk of nerve damage.
The main symptom of sciatica is pain that travels from your lower back (lumbar spine) to your buttock, and down the back of your leg. For some patients, the pain is a mild ache, while others experience a sharp burning pain or a severe jolt of pain. Coughing, sneezing, and sitting for long periods of time may make the pain worse. Sciatica can also cause numbness or muscle weakness along the path of your sciatic nerve into your leg or foot. A tingling or 'pins-and-needles' feeling in your toes or part of your foot is a common symptom. In extreme cases, sciatica can cause a loss of bladder or bowel control, which requires emergency treatment.
Your doctor will ask questions in regards to your medical history and then perform a physical exam. The doctor will also do a muscle test to check your strength and reflexes. In most cases, mild sciatica can improve on its own. Your doctor may order additional diagnostic tests if you have severe chronic pain or a serious medical condition, like cancer, that could cause complications. These tests include X-rays to check the bones in your lower spine, an MRI to check for herniated discs, a CT scan, or a myelogram to look at your spinal cord and nerves.
Sciatica usually responds well to conservative treatments including hot and cold packs, stretching, exercise, and over-the-counter pain medications. Physical therapy is often recommended if a herniated disc is causing your sciatica. Your doctor may also prescribe pain medications or an epidural steroid injection. More aggressive treatments are usually only recommended when conservative treatment doesn't relieve your symptoms.
Surgery for sciatica is usually performed in cases where symptoms have not resolved after 6 weeks of treatment. When a herniated disc is the cause of the pain, your doctor will perform surgery to remove part of the herniated disc that is pressing on your sciatic nerve. This will decompress the sciatic nerve root and reduce the risk that your disc may herniate again.