I was diagnosed with a bulging disk. how did i get hurt?

Hard to tell: Bulging discs are a normal part of aging. They can happen spontaneously or as a result of injury. Particularly between your late 20s and 50s you are become more susceptible to disc issues.

Bulging Disc: Bulging discs are usually caused from a compressive or twisting force on the disc outer covering. The covering is weakened and the disc material squeezes out of its usual location. Bulging can also occur over a long time from slow degeneration of the disc structure.