Fishy urine may be caused by physiological factors, urinary tract infections, rectal vesicovaginal fistula, diabetic ketoacidosis and other factors. 1. physiological factors: diet a lot of durian and other foods, and drink less water, may lead to fishy urine, but there is no other clinical manifestations, should improve the diet, drink more water and more urination, to be able to recover on their own. 2. Urinary tract infections: for example, cystitis, when the infection is aggravated, the presence of a large number of purulent substances in the urine, which may lead to a foul smell of urine, accompanied by pain in urination, urinary frequency, urinary urgency and other symptoms. 3. Rectal vesicovaginal fistula: the existence of rectal vesicovaginal fistula, there may be part of the feces will enter the urine, after urination may make the urine in the presence of obvious fishy odor, may also be repeatedly induced cystitis. 4. diabetic ketoacidosis: diabetes, long time improper use of medication, diabetes continues to aggravate, may induce ketoacidosis, may make the urine fishy odor, manifested as rotten apple flavor, accompanied by drinking, fatigue and other symptoms. In summary, the urine fishy odor and accompanied by other abnormal manifestations, may be the existence of disease factors, it is recommended to seek medical examination and treatment.