Sciatica is a condition that causes pain, weakness, numbness, or tingling in the leg, and it is caused by injury to or pressure on the sciatic nerve. The sciatic nerve is the longest and thickest nerve in the body, and it branches from the lower back through the hips and buttocks and down each leg. The most common cause of sciatica is a herniated disk or an overgrowth of bone that puts pressure on part of the nerve, causing inflammation, pain, and often some numbness in the affected leg. Other causes of sciatica include age-related changes in the spine, such as herniated disks and bone spurs, obesity, a job that requires twisting the back, carrying heavy loads or driving a motor vehicle for long periods, and prolonged sitting.

Sciatica pain can be almost anywhere along the nerve pathway, but its especially likely to follow a path from the low back to the buttock and the back of a thigh and calf. The pain can vary from a mild ache to a sharp, burning pain, and sometimes it can feel like a jolt or electric shock. Depending on the location of the compressed nerve, symptoms may worsen when bending over, lifting objects, twisting, sitting down, coughing, or sneezing.

In summary, sciatic nerve pain is caused by injury to or pressure on the sciatic nerve, which can be due to a herniated disk, overgrowth of bone, or other factors. The pain can be felt anywhere along the nerve pathway, and it can range from mild to severe.