Investigating chronic urinary retention

### What you need to know A 68 year old man complains of worsening fatigue, nausea, and loss of appetite. He reports minimal urinary symptoms but has described episodes of night time bed-wetting in recent months. On examination, he looks generally unwell. He has no abdominal pain. His lower abdomen is dull to percussion up to the level of the umbilicus. He is still voiding urine. Urgent blood investigations are arranged by the general practitioner, which reveal an acute kidney injury. Chronic urinary retention is a common presentation in men in primary care. Women are less commonly affected.1 The condition is frequently not recognised, as symptoms often progress slowly and are not serious. Patients with acute urinary retention are not voiding urine and are in pain.2 In contrast, patients with chronic retention void without pain. Chronic urinary retention has two subtypes: low pressure chronic retention (LPCR) and the more serious, but less common, high pressure chronic retention (HPCR).3 The terms “high” and “low” refer to the bladder pressure at the end of voiding, but pragmatically, HPCR refers to patients with abnormal renal function and/or hydronephrosis, and people with LPCR have normal kidney function and normal kidneys. Acute-on-chronic retention occurs when a patient with chronic retention stops voiding completely. In this article, we present an approach for non-specialists to investigate chronic urinary retention in men and identify high pressure chronic retention, which warrants immediate specialist referral. Patients …