Urinary toxicity occurs primarily in people who use large amounts of ketamine routinely, with 20–30% of frequent users having bladder complaints. It includes a range of disorders from cystitis to hydronephrosis to kidney failure. The typical symptoms of ketamine-induced cystitis are frequent urination, dysuria, and urinary urgency sometimes accompanied by pain during urination and blood in urine. The damage to the bladder wall has similarities to both interstitial and eosinophilic cystitis. The wall is thickened, and the functional bladder capacity is as low as 10–150 mL.