The sciatic nerve is the longest nerve in the body. It consists of five nerve roots that start from the lower back, going through your pelvis, and down through the thigh, knee, calf, ankle, foot, and to your toes.

When the sciatic nerve inflames, it is a medical condition called sciatica. This condition causes intense pain down the lower portion of the body. This condition can cause a loss of reflexes, and can make tasks such as walking, sitting, turning, or standing up very difficult.