The most common cause of a bulging disk is the result of aging, according to Mayo Clinic. Aging causes the spinal disks to lose water and makes them more susceptible to wear-and-tear injuries. In most cases, it is difficult to identify the exact occurrence of the injury.
As disks lose their hydration, cracks and tears occur in the outer fibrous layer. As these cracks grow larger, the thick gel center begins to leak through them. This leaking gel causes the disk to bulge. Over time, the gel has the potential to break through the layer, causing a herniated disk, according to WebMD.
Disk problems affect between 60 and 80 percent of people at some time. The initial pain usually begins in the back, but in the case of sciatica, it sometimes extends down one or both legs. In most cases, bulging disks get better on their own without surgery, according to the American Academy of Orthopedic Surgeons. The healing process sometimes requires a few weeks or months.
Some people have a genetic predisposition for disk problems, according to Mayo Clinic. Others have jobs that require repetitive bending or stretching, which puts additional force on the spine, accelerating the wear on the disks. Overweight patients are at a higher risk of developing disk problems.