National Board of Chiropractic Examiners (NBCE) Practice Test

Which condition is most likely to cause oliguria?

1. Acute renal failure

2. Prostatic hypertrophy

3. Diabetes insipidus

4. Hypercalcemia

The correct answer is: Prostatic hypertrophy

Oliguria, which is defined as a decreased output of urine, can result from a variety of medical conditions. The most likely cause among the options provided is acute renal failure. This condition directly affects kidney function, leading to a significant decrease in the kidneys' ability to filter waste and produce urine. In acute renal failure, there is often an abrupt decline in glomerular filtration rate (GFR), which can be triggered by various factors, including obstruction (pre-renal), damage to the renal tissue (intrinsic), or post-renal complications. This diminished filtering capability results in reduced urine production, making it a classic presentation of oliguria. While prostatic hypertrophy can cause urinary retention and issues with urination, it does not typically lead to oliguria as a direct result. Instead, it may cause a disruption in urine flow rather than a significant reduction in urine output from the kidneys themselves. The other conditions listed—diabetes insipidus and hypercalcemia—also do not primarily cause oliguria. Diabetes insipidus is characterized by polyuria, which is an increase in urine output due to a lack of antidiuretic hormone (ADH) or resistance to it, while hypercalcemia can lead to increased