Sciatica refers to pain that radiates along the path of the sciatic nerve and its branches — from your back down your buttock and leg. The sciatic nerve is the longest nerve in your body. It runs from your spinal cord to your buttock and hip area and down the back of each leg.
Sciatica is a symptom, not a disorder. The radiating pain of sciatica signals another problem involving the nerve, such as a herniated disk.
Pain that radiates from your lower (lumbar) spine to your buttock and down the back of your leg is the hallmark of sciatica. You may feel the discomfort almost anywhere along the nerve pathway, but it's especially likely to follow a path from your low back to your buttock and the back of your thigh and calf.
The pain can vary widely, from a mild ache to a sharp, burning sensation or excruciating discomfort. Sometimes it may feel like a jolt or electric shock. It may be worse when you cough or sneeze, and prolonged sitting can aggravate symptoms. Usually only one lower extremity is affected.
Sciatica symptoms include:
Pain. It's especially likely to occur along a path from your low back to your buttock and the back of your thigh and calf.
Numbness or muscle weakness along the nerve pathway in your leg or foot. In some cases, you may have pain in one part of your leg and numbness in another.
Tingling or a pins-and-needles feeling, often in your toes or part of your foot.
A loss of bladder or bowel control. This is a sign of cauda equina syndrome, a rare but serious condition that requires emergency care. If you experience either of these symptoms, seek medical help immediately.
When to see a chiropractic doctor
You experience sudden, severe pain in your low back or leg and numbness or muscle weakness in your leg
The pain follows a violent injury, such as a traffic accident
Your sciatic nerve branches from your spinal cord through your hips and buttocks and down the back of each leg. This nerve controls many of the muscles in your lower legs and provides feeling to your thighs, legs and feet. Sciatica may develop when a nerve root is compressed in your lower (lumbar) spine — often as a result of a herniated disk in your lower back.
Disks are pads of cartilage that separate the bones (vertebrae) in your spine. Filled with a gel-like substance, they keep your spine flexible and act as shock absorbers to cushion the vertebrae when you move.
If the outer covering of a disk tears (herniates), gel may seep out and press on a nerve root, causing pain in your back, leg or both. If the damaged disk is in the lower part of your back, you may also experience numbness, tingling or weakness in your buttock, leg or foot.
Although a herniated disk is a common cause of sciatic nerve pain, other conditions also can put pressure on your sciatic nerve, including:
Lumbar spinal stenosis
Spinal stenosis is a narrowing of one or more areas in your spine — most often in your upper or lower back. When the narrowing occurs in the lower spine, the lumbar and sacral nerve roots may be affected.
Spondylolisthesis. This condition, often the result of degenerative disk disease, occurs when one vertebra slips slightly forward over another vertebra. The displaced bone may pinch the sciatic nerve where it leaves your spine.
Piriformis syndrome. The piriformis muscle starts at your lower spine and connects to each thighbone (femur). Piriformis syndrome occurs when the muscle becomes tight or goes into spasms, putting pressure on the sciatic nerve. Prolonged sitting, car accidents and falls can contribute to piriformis syndrome.
Spinal tumors. In the spine, tumors can occur inside the spinal cord, within the membranes (meninges) that cover the spinal cord, or in the space between the spinal cord and the vertebrae. As it grows, a tumor compresses the cord itself or the nerve roots.
Trauma. A car accident, fall or blow to your spine can injure the lumbar or sacral nerve roots.