The facet joints are a set of joints located between each pair of vertebrae, one on each side of the spine. Due to injury, aging, pressure overload (or a combination of all of the above), the facet joint begins to wear down and remodel. Sometimes as the remodeling occurs, it may touch one of the nerves coming out of your back and cause pain. The degeneration of the facet joint itself can also be the source of the pain.