A herniated disc (also referred to as a protruding or extruded disc) is a condition where a portion of the gel-like center of the disc has migrated through the layers of the annulus fibrosus. This can cause mechanical pressure on neighboring structures and trigger chemical reactions resulting in pain and inflammation. These changes will often irritate the nerves, producing numbness or tingling in the legs or feet. Left untreated, this condition may result in life-changing pain and physical disability.
Degenerative disc disease is a state of dehydration and deterioration marked by the gradual erosion of the discs ability to distribute and resist mechanical loads. As discs deteriorate, they become more prone to injury from physical stress. Degenerative disc disease may also play a contributing role in conditions such as disc bulges, disc herniations, and stenosis.
Facets are the posterior joints of the spine that aid in keeping the vertebrae aligned. Facet syndrome can result from injury or degeneration of the disc and is characterized by pain, stiffness, and inflammation. The pain generally increases with motion and is relieved by rest.
Sciatica is a condition often associated with
a herniated or ruptured disc. When the injured disc compresses one of
the spinal nerves 
leading to the sciatic nerve, it can produce a
shock-like pain that travels through the buttocks and down one leg to
below the knee. Tingling and numbness are common in this condition.
Sciatica can occur suddenly, or develop gradually. The pain and symptoms
of sciatica can be intensified by coughing, sneezing, or sitting in the
same position for prolonged periods of time.
