Causes of Sciatica varies from person to person. There are spinal stenosis, spondylolisthesis, spinal tumors, herniated disc, piriformis syndrome and spinal stenosis. For some people the sciatic pain may last for four weeks to six weeks but the other problems associated with it lingers. For example  weakness in the muscle or muscles becoming numb remains with it. Any kind of compression in the sciatic nerve roots is considered to be the most important causes of sciatic pain. The Sacral nerve roots such as S1 or S2 or S3 or if L4 or L5 of lumbar spine nerve roots are often affected. If there is any kind of compression or irritation in the nerve roots then there are chances of sciatic pain.