The sciatic nerve is the longest and thickest nerve in the body. It begins in the lower back, known as the lumbar region. From there, this nerve splits into two sections, each traveling through the buttock, down the leg, and to the foot. The sciatic nerve supplies nervous system energy to the thighs, lower legs, and feet. Symptoms that result from sciatic nerve compression are referred to as sciatica. We’ll discuss this common back problem here.
Pain at the back of the thigh, buttock, or calf is a common sign of sciatic nerve compression. A person may also experience tingling, burning, weakness, or numbness in these areas or the foot. The discomfort is typically felt only on one side of the body.
What Causes Sciatica?
The low back is the origin of sciatica because that is where the sciatic nerve begins. Common conditions that affect the lumbar region of the spine include:
- A herniated disc. Each set of spinal bones (vertebrae) are separated by an intervertebral disc. This disc is tough on the outside and soft on the inside so that it moves with the natural motions of the spine. Discs are the shock absorbers of the spine that prevent nerve compression and friction between two vertebrae. As a result of disease, injury, or age-related wear and tear, a disc may protrude into the spinal canal or press against a nerve root. In the lumbar spine, it is the sciatic nerve that may suffer compression.
- Degenerative disc disease. This chronic condition involves gradual, ongoing deterioration of disc structure. Over time, the disc may get thinner and thinner, narrowing the space it is supposed to fill. Often, degenerative disc disease is the precursor to disc herniation or lumbar spinal stenosis.
- Spinal stenosis. The vertebrae that form the spinal column should be perfectly aligned so that the spinal cord can travel through a canal created through their central structure. Spinal stenosis is the narrowing of this canal and subsequent compression of the spinal cord at the point where stenosis has occurred.
A doctor may diagnose sciatica based on the pain reported by a patient. However, the consultation only identifies that the sciatic nerve is being pinched. It does not determine why. To identify the cause of sciatica, a doctor may order x-rays, a CT scan, or an MRI. Once the caused has been found, a spinal specialist can develop a treatment plan based on the patient’s needs and preferences. Surgery is typically the last resort for sciatic nerve pain.