What causes sciatica?
Sciatica is caused by irritation of the sciatic nerve. A slipped disc is the most common cause of sciatica.
Additional common causes of sciatica include:
Lumbar spinal stenosis (narrowing of the spinal canal in the lower back)
Degenerative disc disease (breakdown of discs, which act as cushions between the vertebrae)
Spondylolisthesis (a condition in which one vertebra slips forward over another one)
Pregnancy
Other things that may make your back pain worse include being overweight, not exercising regularly, wearing high heels, or sleeping on a mattress that is too soft.