Over time we will get degeneration in our spine no matter what. Just from our job, daily activities, and life in general etc . . . your body will have some wear and tear. However, that degeneration should be minimal and not cause major back pain. If we get degeneration to the point a disc is worn completely out however, there is a good chance there will be pain.
What usually happens is that an injury happens to part of your back (one of your discs may sustain an injury); then over the years, wear and tear and stress accumulates at that “weak spot”, so to speak.
Often times then something irritates that disc enough to cause nerve pressure and pain. Often, we have some arthritis, misalignments, a bulged or protruded DISC, and inflammation, that clog up the area where the nerve, nerve root, or nerves travel.
When a disc ruptures it usually happen posterior-laterally, which is exactly where the neural foramen are (where the nerves branch off the cord and exit the spine). Now a disc can herniated or bulge directly laterally, or maybe to the anterior (front), but it may not put direct pressure on a nerve and you may not have pain.
Here’s an example: Mike never had serious back pain before, but after a bunch of yard work one day he had pain that never left. The next day he started to get pain down his right leg too. If it wasn’t hurting or a pain feeling, he would often feel a tingling sensation. (By the way, it's analogous to the neck, meaning this could be an example of neck and arm pain...)
Mike was sent for an x-ray which didn’t show much, but since pain still persisted he was sent for an MRI. That picture did reveal a lower back disc that was herniated off to the posterior and right.
This makes sense because his pain is on the right. The reason the x-ray didn’t show much is because you can only see the bones and not the disc, hence the reason for the MRI.
To go back to our title: that particular disc in back most likely was irritated, or slightly worn down, maybe from years of wear and tear, and then fully herniated or ruptured from doing a lot of physical work that stressed that area…
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