A spinal cord injury is defined as damage to the spinal cord that leads to neurological deficits -- such as paralysis, weakness, numbness, or an inability to control bowel and bladder functions. The spinal cord can be injured by: (1) direct trauma (accident or fall); (2) loss of sufficient blood supply due to internal bleeding, prolonged compression from a herniated disc, or infected abscess that was not timely diagnosed and treated; (3) direct injury from surgical instruments. Often a delay in the treatment of a spinal cord injury transforms a temporary problem into a permanent disabling condition. Spinal cord injuries typically involve injury to the vertebrae, which are the rings of bones that surround the spinal cord and make up the spinal column. The vertebrae are named according to their location in the spinal column. There are seven cervical (neck), twelve thoracic (back), five lumbar and five sacral (lower back) vertebrae. Cervical spinal cord injuries usually cause loss of function in both the arms and legs, resulting in tetraplegia. Thoracic spinal cord injuries usually affect the chest and the legs; and Lumbar and Sacral injuries affect the hips and legs, resulting in paraplegia.