Degenerative disc disease, as the name explains, is the resulting pain of discs degenerating or deforming in shape over time. There are many reasons for discs to degenerate, injury, infection, smoking, aging being the most common cause found among patients.
A degenerated disc also causes the vertebra bone to significantly grow, also known as a bone spur or osteophytes. This increased bone structure then causes spinal or foraminal stenosis-narrowing causing pain and restricting movement.
Degenerative disc disease is NOT really a disease; it is a misnomer. With several symptoms and severity of the resulting pain, there is no set definition for degenerative disc disease found, and pain management specialists have varying opinions on the matter.