A common cause of low back and leg pain is a ruptured or herniated disc. Disc herniation occurs when the annulus fibrous breaks open or cracks, allowing the nucleus pulposus to escape. This is called a Herniated Nucleus Pulposus (HNP) or herniated disc.Symptoms may include dull or sharp pain, muscle spasm or cramping, sciatica, and leg weakness or loss of leg function. Sneezing, coughing, or bending usually intensifies the pain. Rarely bowel or bladder control is lost, and if this occurs, seek medical attention at once. Sciatica is a symptom frequently associated with a lumbar herniated disc. Pressure on one or several nerves that contribute to the sciatic nerve can cause pain, burning, tingling, and numbness that extends from the buttock into the leg and sometimes into the foot. Usually one side (left or right) is affected.