Sciatica: Symptoms and Possible Causes
The term sciatica is commonly used to describe pain traveling in the distribution of the sciatic nerve, so it’s more accurate to say that it’s a symptom of a spinal disorder not a spinal disorder itself. Common symptoms of sciatica include:
- Sciatica usually affects one side of the body.
- Pain from sciatic nerve compression may feel dull, sharp, burning, or accompanied by intermittent shocks of shooting pain beginning in the buttock and traveling downward into the back and/or side of the thigh and/or leg.
- Sciatica extends below the knee and may be felt in the feet.
- Sometimes symptoms of sciatic nerve compression include tingling and numbness.
- Sitting and trying to stand up may be painful and difficult.
- Coughing and sneezing can intensify the pain.
Where is the Sciatic Nerve?
Sciatic nerve fibers begin at the 4th and 5th lumbar vertebra (L4, L5) and the first few segments of the sacrum. The nerve passes through the sciatic foramen (a nerve passageway) just below the piriformis muscle (rotates the thigh laterally), to the back of the extension of the hip and to the lower part of the gluteus maximus (muscle in the buttock, helps with thigh extension).
The sciatic nerve then runs vertically downward into the back of the thigh, behind the knee and branches into the hamstring muscles (calf) and further downward to the feet.
Nerve Compression Can Cause Sciatica
Compression of the sciatic nerve can cause any of the above-cited symptoms. Rarely is nerve damage permanent, and paralysis is seldom a danger since the spinal cord ends before the first lumbar vertebra.
- When to seek emergency medical care: Increasing trunk or leg weakness or bladder and/or bowel incontinence is an indication of cauda equina syndrome, a serious disorder requiring emergency treatment. If you are experiencing those symptoms right now, please seek immediate medical treatment.
Certain lumbar (low back) spinal disorders can cause or contribute to sciatica symptoms, and include:
- Herniated discs are the most common cause of sciatica in the lumbar spine.
- Degenerative disc disease, a natural biological process associated with aging, is known to cause disc weakness that can be a precursor to a disc herniation.
- Lumbar spinal stenosis is a narrowing of one or more neural passageways due to disc degeneration and/or facet arthritis. The sciatic nerve may become impinged as a result of these changes.
- Isthmic spondylolisthesis results from a stress fracture often at the 5th lumbar vertebra (L5). The fracture combined with disc space collapse may allow the vertebra to slip forward on the first sacral segment (S1). The slippage may cause the L5 nerve root to become pinched as it leaves the spine.
- Spinal tumors and infections are other disorders that may compress the sciatic nerve, but this is rare.
How Your Doctor Diagnoses Sciatica
Your doctor’s evaluation of your pain and other symptoms includes discussing your medical history, recent accidents or injuries (eg, falls), and a review of your current medications (both over-the-counter and prescription). He will perform a physical evaluation using one or more movement tests to help determine the source or causes of your pain. During the neurological part of the examination, your reflexes and muscle strength are tested. If necessary, he will order imaging studies, such as an x-ray, CT scan, or potentially an MRI. The imaging tests may help confirm your diagnosis.
Your doctor may ask you several questions, such as:
- “How did the pain develop?”
- “On a scale from 1 to 10, with 10 being the worst pain imaginable, rate your pain.”
- “Is the pain worsened by walking uphill or downhill?”
- “How does the pain affect activities of daily living?”
- “What type of treatment has been tried and what was effective?”