Sciatica, which is also known as sciatic neuralgia, is a condition that causes pain in the lower back, down the back of the leg, and into the foot. It can make sitting and standing for long periods of time difficult and can lead to weakness, tingling, and numbness in the leg and foot. It will often come and go throughout a person's lifetime, causing periods of varying degrees of pain and discomfort. If left unchecked, sciatic pain will generally grow worse and the nerve can become permanently injured.
The reason why the pain travels so far, seems to radiate up and down the legs and back, is because it is caused by the compression of the sciatic nerve, the longest nerve in the body. This nerve originates in the lumbar spine and extends into the buttocks before traveling down the leg to the ankle and foot. When the vertebrae in the low back are compressed, the roots of the sciatic nerve can become pinched and irritated which is what causes the pain and injury.