Urinary retention, also known as ischuria, is an inability to completely empty the bladder. It is a common complication of benign prostatic hyperplasia (BPH), though it can also be caused by:
Tethered spinal cord syndrome
Medications (including anticholinergics, antidepressants, COX-2 inhibitors, amphetamines, and opioids)
Diagnosis and treatment may require a catheter or prostatic stent.