The intervertebral discs are under constant pressure. As discs degenerate and weaken, cartilage can bulge or be pushed into the space containing the spinal cord or a nerve root, thus causing pain. Studies have shown that most bulging discs occur in the lower lumbar portion of the spinal column. A bulging disc is also called protruding, herniated, or ruptured disc.
Cauda Equina Syndrome
A much more serious complication of a ruptured disc is cauda equina syndrome, which occurs when disc material is pushed into the spinal canal and compresses the bundle of lumbar and sacral nerve roots. Permanent neurological damage may result if this condition is left untreated.
Sciatica
Sciatica is a condition in which a herniated or ruptured disc presses on the sciatic nerve, the large nerve that extends down the spinal column to its exit point in the pelvis and carries nerve fibers to the leg. This compression causes shock-like or burning lower back pain combined with pain through the buttocks and down one leg to below the knee, occasionally reaching the foot. In the most extreme cases, when the nerve is pinched between the disc and an adjacent bone, the symptoms involve not pain, but numbness and some loss of motor control over the leg due to an interruption in nerve signaling. The condition may also be caused by a tumor, cyst, metastatic disease, or degeneration of the sciatic nerve root.