Sciatica refers to pain that travels along the path of the sciatic nerve. The sciatic nerve travels from the buttocks and down each leg.Sciatica most often happens when a herniated disk or an overgrowth of bone puts pressure on the lumbar spine nerve roots. This happens "upstream" from the sciatic nerve. This causes inflammation, pain and often some numbness in the affected leg.

Symptoms: 

Sciatica pain can be almost anywhere along the nerve pathway. It's 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. Sometimes it feels like a jolt or electric shock. It can be worse when coughing or sneezing or sitting a long time. Usually, sciatica affects only one side of the body.

Some people also have numbness, tingling, or muscle weakness in the leg or foot. One part of the leg can be in pain, while another part can feel numb.