Several forms of injury affect the vertebral discs. Disc bulges, for instance, are more broad-based injuries, while disc herniations tend to be more focal. Complete tears of the annulus result in disc extensions, while free fragments of the annulus cause disc sequestrations. All of these forms of disc injury can cause pain in both the back and extremities, and the symptoms worsen as the injuries progress from bulges to sequestrations. Most commonly, pain is due …showed first 75 words of 298 total…

…showed last 75 words of 298 total…sinuvertebral nerve. In addition, studies have shown that mechanoreceptors, nociceptors, and chemoreceptors all detect changes in the disc due to distension of the disc. These conditions may all further heighten the sense of pain. Phospholipase A, bradykinin, histamine, and other chemicals and enzymes present during disc injuries influence the chemoreceptors that may cause the pain of disc protrusions. Other studies have also correlated inflammation and edema to the pain associated with disc bulges and herniations.