Retention

The sudden inability to urinate is usually symptomatic of another condition that requires treatment. It may be caused by obstructions in the bladder or urethra (the tube that carries urine from the bladder outside the body), by a disruption of sensory information in the nervous system (e.g. spinal cord or nerve damage), or by swelling of the bladder (e.g. by delaying urination for a long period of time). Besides a clear and sudden inability to void the bladder, people with acute urinary retention usually experience a distended abdomen.  

Complications of untreated urinary retention can include bladder damage and chronic kidney failure. Treatment is draining the bladder of urine with intermittent catheterisation along with treatment of the underlying cause.