Synonyms. The terms bulging disk, slipped disk, herniated disk are roughly the same idea that they disc has moved out of place where it should be and possibly compressing nerve or spinal cord. Typically though herniated disk signifies a slight increase in severity of pathology over a bulging disc. It gets a little more specific if terms like disc protrusion and disc extrusion come into the mix.
Symptoms and size. A bulging disc is similar to your tire that has lost some air and the sidewall bulges. It may cause no symptoms but if it bulges more and is large even to pinch a nerve we use the term herniated disc. It is confusing for patients and for doctors who read the reports. The patients' history and clinical exam must be correlated with the x-rays.
Usually. There are not absolute definitions for either a herniated or bulging disc. What I may call a bulging disc another doctor might call herniated. In general though a herniated disc is actually protruding or hanging out of the normal disc space. A bulging disc is protruding less. Think of a drop of water, the bulging disc is the drop about to fall and the herniated disc is the drop that is falling.
Yes. Disc bulges are normal variants of a disc, not an issue that should cause a problem almost like the way radial tires on a car bulge a little to the sides as they contact the road. This occurs with disc loading as well. A disc herniation is an actual disruption of the disc's coating layers allowing disc material to move out of a normal position. This is a more frequent finding as we age.
Size. Bulging discs are normal findings on imaging studies while disc herniations are discs that have moved out of there normal position. Disc bulges do not cause symptoms. A disc herniation is an actual passage of the disc's inner core or nucleus passing thru the outer part or annulus of the disc where a disc bulge does not result in any part if the disc out of its normal alignment of material.
Disc bulge herniatio. A bulging disc occurs with degeneration or minor disruption of the disc complex. A bulge usually doesn't contact or compress the spinal cord or nerve root and can be an a symptomatic finding. A herniated disc is a bigger disc disruption usually associated with mass effect on the spinal cord or nerve root. Weakness, sensory loss, or pain down the extremity is usually found.