A health disc is a two dimensional round or oval structure having four (4) 90-degree quadrants. Think of a pizza pie cut into 4 equal pieces. The discs sit between the vertebra and act as shock absorbers. A herniated disc occurs when the jelly-like disc material leaves the center of the disc. The chemicals from the disc can leak out acting as an irritant. This usually causes pain. A herniated disc can also indent the spinal canal, causing similar problems.