Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is the mechanism behind overflow incontinence?

1. Involuntary bladder contractions

2. Incomplete bladder emptying

3. Weak pelvic floor muscles

4. Hyperactive bladder activity

The correct answer is: Incomplete bladder emptying

Overflow incontinence occurs primarily due to incomplete bladder emptying. This condition arises when the bladder is unable to fully expel its contents, leading to an accumulation of urine that eventually exceeds the bladder's capacity. As the bladder fills beyond its limit, involuntary leakage occurs, resulting in overflow. This mechanism is often related to factors such as bladder outlet obstruction, weakened bladder muscles, or neurological conditions that affect the bladder's ability to contract effectively. In such cases, despite the urge to urinate, the bladder cannot fully empty, which contributes to the involuntary leakage of urine when the bladder becomes overly distended. The other options relate to different types of urinary incontinence. For instance, involuntary bladder contractions are more characteristic of overactive bladder syndrome rather than overflow incontinence. Weak pelvic floor muscles typically lead to stress incontinence, where leakage occurs during activities that increase abdominal pressure. Hyperactive bladder activity also points more towards urgency and frequent urination rather than the inability to empty the bladder. Understanding these distinctions is important for assessing and treating various forms of incontinence.