Total incontinence is characterized by the constant or periodic loss of urine without normal voiding and no postvoid residual. It can be thought of as a true “leak in the tank.” Causes include major sphincteric abnormalities such as those that occur with exstrophy of the bladder or epispadias, and abnormal anatomic connections such as those that occur with vesicovaginal fistulas or ectopic ureteral orifices.

Stress incontinence is characterized by the involuntary loss of urine not caused by bladder contraction and associated with physical activities such as coughing, laughing, sneezing, lifting, and exercise. This usually occurs in females with weakened pelvic floor support, urethral hypermobility, and descensus of the bladder neck. It is often associated with multiple vaginal deliveries. The net result is a loss of the normal transmission of intra-abdominal pressures to the proximal urethra. Increased intra-abdominal pressures will therefore cause only elevated intravesical pressures and loss of urine because the outlet resistance is unchanged. The cystometrogram is usually normal. Male stress incontinence may
follow major prostate surgery, especially when combined with radiation therapy.

Urge incontinence is the result of an involuntary rise in intravesical pressure secondary to bladder contraction, which overcomes outlet resistance. Bladder instability or hyperreflexia generally produces a sensation of urgency of urination in most patients; however, it can present with incontinence alone. Common causes of detrusor instability include loss of cortical inhibition of the voiding reflex (e.g., those that occur after strokes or dementia or with parkinsonism). However, the more common local causes of detrusor instability, such as infection, bladder stone, tumor (carcinoma in situ), interstitial cystitis, or foreign body, must always be ruled out first.