Urinary retention is the inability to empty the bladder completely. Urinary retention can be acute or chronic. Acute urinary retention happens suddenly and lasts only a short time. People with acute urinary retention cannot urinate at all, even though they have a full bladder. Acute urinary retention, a potentially life-threatening medical condition, requires immediate emergency treatment. Acute urinary retention can cause great discomfort or pain. Chronic urinary retention can be a long- lasting medical condition. People with chronic urinary retention can urinate. However, they do not completely empty all of the urine from their bladders. Often people are not even aware they have this condition until they develop another problem, such as urinary incontinence—loss of bladder control, resulting in the accidental loss of urine— or a urinary tract infection (UTI), an illness caused by harmful bacteria growing in the urinary tract