What causes sudden urinary retention in a teenager?
—FELIX N. CHIEN, DO, Newport Beach, Calif.

Except when associated with an acute dysuria, sudden urinary retention in teenagers is not common. Medications may be the most frequent reason I have observed. Other causes include neurogenic bladder (due to a variety of causes) as well as obstruction along the genitourinary tract (ureters, bladder neck, urethra, meatus) due to trauma, infection, tumor, stones, phimosis, blood, uric acid crystals, or inflammation. A careful history and physical examination may be helpful in providing the etiology before resorting to laboratory and radiologic studies.
— Michael E. Ryan, DO