Your backbone (spinal column) is made up of a chain of bones called the vertebrae. Your spinal cord runs through the spinal column. The bones help protect the cord from injury. Discs sit between each vertebra. The discs give cushioning and support. Large nerves called nerve roots exit from the spinal cord through small holes between the bones. These holes are called foramen. These nerve roots send and receive signals to and from the body. The signals are sent to and from your brain through the spinal cord.
The outer wall of one of these discs may tear and weaken with age or injury. When this happens, the soft inner part of the disc bulges out. This is called a herniated or bulging disc. This bulging disc can press on the spinal cord or the nerve roots. This can cause pain, tingling, difficulty urinating, or weakness in your arms or legs.