Last reviewed 01/2018

History and examination - classically the patient is anuric, in great discomfort and has an intense desire to micturate. The bladder is palpable and there is suprapubic dullness to percussion.

Passing a urethral catheter releases a large volume of urine - more than 500 ml in an adult - which confirms the clinical diagnosis. Passing a catheter helps to exclude renal failure as a cause of anuria.