Its very difficult to trace a HD to a single cause since it is possible to injure the disc initially, and not really notice it until months or years later when the problem is finally diagnosed with the aid of an MRI study.
Some people have a HD and never have any symtoms or pain from it.
Keep in mind that some of these sites are run by doctors, so even though they do contain some real good background material, ultimately they are targeting you to go see them. You can go browse back through the article archives, this will take some time but there is lots of good informtion right here. You can also use the search robot as well. Remember, even if you have recent pain, surgery should be your last and final option before you have tried all other avenues. However, it may take a while.