Overactive bladder is a symptomatic process with signs and symptoms of urgency that may or may not be associated with urge incontinence. It therefore consists of a purely functional, and not anatomical, alteration: it is due to poor detrusor function. The detrusor is, after all, a muscle, and when muscles are overstimulated, they can hypertrophy (Figure 8).
Figure 8. Bladder wall thickness is calculated using the average measurement of the wall to the dome, anterior face and trigone (8).
In 1996, Khullar wondered if bladder wall thickness could be an indicator of overactive bladder (8). Although at first it seemed that a thickness greater than 5 mm was associated with overactive bladder, the matter has been under debate due to the literature's different techniques of measuring the wall (some included only the detrusor in their measurements, others the entire wall, etc.). In light of recent studies, it does not appear that bladder wall thickness contributes a great deal to the diagnosis of overactive bladder (11).
