A disc bulge is caused by weakening of the outside layer of the spinal disc (called the annulus), causing the disc to flatten and balloon into the spinal canal. A disc bulge is less severe than a disc protrusion or a disc herniation where the outer layer breaks.
Also known as: disc herniation, disc protrusion
![](https://www.spineinfo.com/wp-content/uploads/2022/11/Disc-bulge-1024x168.jpg)
![](https://www.spineinfo.com/wp-content/uploads/2022/11/disc-bulge-and-herniation-1024x507.jpg)