Disc degeneration in the spine is common as we age. Doctors gauge how severe the damage is by giving the disc a number from 1 to 5 from best to worst. The grades are usually written in Roman numerals (I to V).

Early degeneration is noted by Grades I and II. Moderate destruction is a III. More severe damage is labeled IV and V. Grade V means the disc is no longer healthy. It has lost its ability to cushion the spine. In fact, the disc may be collapsed with very little space between the bones.

MRIs can show the condition of the two parts of the disc. These include the outer covering called the anulus and the inner core called the nucleus. Damage from aging or injury can result in disc degeneration. The nucleus and annulus are no longer visible on MRI as two separate structures. A very low signal intensity shows up on the MRI with a grade V disc.