In order to provide an agent for treatment of bladder troubles that has vesical mucosa epithelium dilatation promoting action and/or vesical mucosa healing action, and exhibits excellent curative effect for bladder troubles, in particular, non-bacterial intractable bladder troubles, the agent for treatment of bladder troubles is formulated with hyaluronic acid and/or a pharmaceutically acceptable salt thereof, preferably hyaluronic acid and/or a pharmaceutically acceptable salt thereof having the following physicochemical properties: (A) endotoxin content; 0.03 EU (endotoxin unit)/10 mg or less, (B) sulfur content; 0.01% or less as determined by coulometric titration, (C) iron content; 20 ppm or less, (D) protein content; 0.1% or less, and (E) weight average molecular weight; 500,000 or more, in an amount effective for promoting vesical mucosa epithelium dilatation and/or healing vesical mucosa, preferably in an amount of 0.2-0.6% by weight based on total amount of the agent.