What is progressive disc degeneration?

Progressive disc degeneration is something that I myself suffer with wich it is the later stages of disc degeneration desease in wich the disc in your back and/or neck start to deteriate it is useuall caused by over working your back .. lifting the wrong way for too long and a whole lot of things but it over stresses the disc and causes them to deteriate and there for the mame of the desease the working mans desease as I call it