Obstruction of the male urinary tract in older men is most commonly due to which condition?

• A. Prostatitis
• B. Urethral stricture
• C. Carcinoma of the prostate
• D. BPH (periurethral zone)

Answer: (D)

Growth of the transitional (periurethral) zone of the prostate as men age leads to bladder outlet obstruction. This part of the prostate surrounds the urethra, so when it enlarges, it narrows the prostatic urethral lumen and reduces urine flow, producing hesitancy, weak stream, incomplete emptying, and nocturia. While prostatitis, urethral strictures, or prostate cancer can cause urinary issues, they are less common causes of obstruction in older men compared with benign prostatic hyperplasia.