Urinary incontinence - Wetting your pants and bed? involuntary leakage of urine

Definitions

Urinary incontinence (UI):  the complaint of any involuntary leakage of urine.

Stress urinary incontinence (SUI): the complaint of involuntary leakage of urine on effort or exertion or sneezing or coughing. SUI can also be a sign, the observation of involuntary leakage of urine from the urethra that occurs synchronously with exertion, coughing, etc. A diagnosis of urodynamic SUI is made during filling cystometry when there is involuntary leakage of urine during a rise in abdominal pressure (induced by coughing), in the absence of a detrusor contraction.

Urge urinary incontinence (UUI): the complaint of any involuntary leakage of urine accompanied by or immediately preceded by urgency.

Mixed urinary incontinence (MUI): a combination of SUI and UUI.

• Both UUI and MUI cannot be a sign as they both require a perception of urgency by the patient.
• 25% of women aged >20 years have UI of whom 50% have SUI, 10 to 20% pure UUI, and 30 to 40% MUI.
• UI impacts on psychological health, social functioning, and quality of life.

Significance of SUI and UUI

SUI occurs as a result of bladder neck/urethral hypermobility and/or neuromuscular defects causing intrinsic sphincter deficiency (sphincter weakness incontinence). As a consequence, urine leaks whenever urethral resistance is exceeded by an increased abdominal pressure occurring during exercise or coughing, for example.

UUI may be due to bladder overactivity (formerly known as detrusor instability), or less commonly due to pathology that irritates the bladder (infection, tumour, stone). The correlation between urodynamic evidence of bladder overactivity and the sensation of urgency is poor, particularly in patients with MUI. Symptoms resulting from involuntary detrusor contractions may be difficult to distinguish from those due to sphincter weakness. Furthermore, in some patients detrusor contractions can be provoked by coughing, and therefore distinguishing leakage due to SUI from that due to bladder overactivity can be very difficult.

Other types of incontinence

While SUI and especially UUI do not specifically allow identification of the underlying cause, some types of incontinence allow a specific diagnosis to be made.

• Bedwetting in an elderly man usually indicates high pressure chronic retention (HPCR).
• A constant leak of urine suggests a fistulous communication between the bladder (usually) and vagina (e.g. due to surgical injury at the time of hysterectomy or caesarian section) or, rarely, the presence of an ectopic ureter draining into the vagina (in which case the urine leak is usually low in volume, but lifelong).