What causes sciatic back pain?

Sciatica is a condition caused by an irritation of the nerve roots in the lower lumbar and lumbosacral spine, according to WebMD. Other causes of the condition include lumbar spinal stenosis, degenerative disc disease, spondylolisthesis and pregnancy.

Sciatica only affects one side of the lower body, with pain extending from the lower back down through the back of the leg, according to WebMD. Sciatica symptoms include pain in the buttocks or the back of the leg that worsens when sitting, burning or tingling in the leg, weakness in the leg, constant pain on one side of the rear and shooting pains down the leg that make standing difficult.