Urine odor is most likely to be a urinary tract infection, ketoacidosis, but also may be a physiological phenomenon. 1. Urinary tract infections: If you do not pay attention to personal hygiene, frequent unclean sex and decreased body resistance can easily lead to urinary tract infections, such as inflammation of the urethra, nephritis, and cystitis and other infectious diseases, the inflammation caused by bacteria will stimulate the bladder and lead to the production of smelly urine. 2. Diabetic ketoacidosis: Because of the increase in blood sugar, fat decomposition increases, and fatty acid metabolites finally become acetone. Because of the chemical nature of acetone, the smell has a rotten apple flavor, so patients with diabetic ketoacidosis have a rotten apple smell in their breath and urine. 3. Physiological phenomenon: urine odor may also be a physiological phenomenon, is due to the concentration of urine, mainly due to various reasons for the intake of water is too small as well as the loss of water is too much, in this case, just need to drink more water to improve the symptoms. Urine odor may also be caused by other factors, it is recommended that the patient in the exclusion of physiological factors in a timely manner to the regular hospital consultation and treatment, and strive for early recovery.