It may be associated with neurological dysfunction, such as weakness and numbness. Causes
Risk factors
Modifiable risk factors for sciatica include smoking, obesity, occupation, and physical sports where back muscles and heavy weights are involved. Non-modifiable risk factors include increasing age, being male, and having a personal history of low back pain. Spinal disc herniation
Spinal disc herniation pressing on one of the lumbar or sacral nerve roots is the most frequent cause of sciatica, being present in about 90% of cases. This is particularly true in those under age 50. Disc herniation most often occurs during heavy lifting. Pain typically increases when bending forward or sitting, and reduces when lying down or walking. Spinal stenosis
Other compressive spinal causes include lumbar spinal stenosis, a condition in which the spinal canal, the space the spinal cord runs through, narrows and compresses the spinal cord, cauda equina, or sciatic nerve roots. This narrowing can be caused by bone spurs, spondylolisthesis, inflammation, or a herniated disc, which decreases available space for the spinal cord, thus pinching and irritating nerves from the spinal cord that become the sciatic nerve. This is the most frequent cause after age 50. Sciatic pain due to spinal stenosis is most commonly brought on by standing, walking, or sitting for extended periods of time, and reduces when bending forward. However, pain can arise with any position or activity in severe cases. The pain is most commonly relieved by rest.
Physical activity
Physical activity is often recommended for the conservative management of sciatica for persons who are physically able. However, the difference in outcomes between physical activity compared to bed rest have not been fully elucidated. The evidence for physical therapy in sciatica is unclear though such programs appear safe. Physical therapy is commonly used. Nerve mobilization techniques for sciatic nerve is supported by tentative evidence. Medication
There is no one medication regimen used to treat sciatica. Evidence supporting the use of opioids and muscle relaxants is poor. Low-quality evidence indicates that NSAIDs do not appear to improve immediate pain, and all NSAIDs appear to be nearly equivalent in their ability to relieve sciatica. Nevertheless, NSAIDs are commonly recommended as a first-line treatment for sciatica. In those with sciatica due to piriformis syndrome, botulinum toxin injections may improve pain and function. While there is little evidence supporting the use of epidural or systemic steroids, systemic steroids may be offered to individuals with confirmed disc herniation if there is a contraindication to NSAID use. Low-quality evidence supports the use of gabapentin for acute pain relief in those with chronic sciatica. Anticonvulsants and biologics have not been shown to improve acute or chronic sciatica. Antidepressants have demonstrated some efficacy in treating chronic sciatica, and may be offered to individuals who are not amenable to NSAIDs or who have failed NSAID therapy. Surgery
If sciatica is caused by a herniated disc, the discs partial or complete removal, known as a discectomy, has tentative evidence of benefit in the short term.