Disc Prolapse, also known as herniated disc, happens when the softer part of the disc that is found in the spinal cord protrudes from the disc, touching delicate nerves which can cause pain and swelling. How does it happen? Between every vertebrae in the spinal column are discs that act as shock absorbers during movements, physical activities, and the like. Inside these discs are soft, gel-like substances called nucleus pulposus. Disc prolapse happens when this gel-like substance sticks out of the discs.