What is a common cause of postrenal failure?

Postrenal failure occurs when there is an obstruction in the urinary tract that prevents urine from being excreted. This type of failure happens after the kidneys, which is why the term "postrenal" is used. One of the most common causes of this obstruction is prostate disease, particularly benign prostatic hyperplasia (BPH) or prostate cancer. These conditions can lead to an enlarged prostate that compresses the urethra, making it difficult for urine to flow from the bladder.

As a result, the kidneys can become backed up with urine, leading to increased pressure and potential kidney damage if the obstruction isn't resolved. Understanding the anatomical relationship between the prostate and the urinary tract is essential in recognizing how prostate disease can lead to postrenal failure.

Other conditions, like renal trauma, fluid volume shifts, or kidney infections, while they can affect renal function, do not typically create the same type of obstruction that is characteristic of postrenal causes. This highlights why prostate disease is a critical consideration in the differential diagnosis of postrenal failure.