<unk>  is an injury to the cushioning and connective tissue between vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physical disability. The most conclusive diagnostic tool for<unk><unk>  is MRI, and treatment may range from painkillers to surgery. Protection from<unk><unk>  is best provided by core strength and an awareness of body mechanics including posture. When a tear in the outer, fibrous ring of an intervertebral<unk>  allows the soft, central portion to bulge out beyond the damaged outer rings, the<unk>  is said to be herniated.<unk><unk>  is frequently associated with age-related degeneration of the outer ring, known as the annulus fibrosus, but is normally triggered by trauma or straining by lifting or twisting. Tears are almost always posterolateral (on the back sides) owing to relative narrowness of the posterior longitudinal ligament relative to the anterior longitudinal ligament. A tear in the<unk>  ring may result in the release of chemicals causing inflammation, which can result in severe pain even in the absence of nerve root compression.<unk><unk>  is normally a further development of a previously existing<unk>  protrusion, in which the outermost layers of the annulus fibrosus are still intact, but can bulge when the<unk>  is under pressure. In contrast to a<unk> , none of the central portion escapes beyond the outer layers. Most minor<unk> s heal within several weeks. Anti-inflammatory treatments for pain associated with<unk><unk> , protrusion, bulge, or<unk>  tear are generally effective. Severe<unk> s may not heal of their own accord and may require surgery. The condition may be referred to as a slipped<unk> , but this term is not accurate as the spinal<unk> s are firmly attached between the vertebrae and cannot "slip" out of place.
Spinal disc herniation
Piriformis syndrome
Spinal tumor
Lumbar disc disease
Spinal stenosis
Degenerative disc disease
Lumbar spinal stenosis
Cervical spinal stenosis