Sciatica is caused by the root(s) of the lower lumbar and lumbosacral spine getting irritated.
Extra common causes of sciatica are:
Lumbar spinal stenosis (The narrowing of the spinal canal at the lower back)
Degenerative disc disease (Breakdown of discs, which are like cushions between your vertebrae)
Spondylolisthesis (Where one vertebra slips over another vertebra)
Other ways to make your back pain worse are being overweight, not exercising enough, wearing high heels, or sleeping on a mattress that’s too soft.