If you have a bad odor, there are usually several factors: 1. If you have hepatitis or cirrhosis or acute jaundice hepatitis, you will have a bad odor called liver odor in your breath because the sulfide in your body cannot be metabolized by your liver, resulting in gas and odor. 2. 3, in the seriousness of diabetes mellitus combined with ketosis, will appear in the breath rotten apple smell, there will be a very bad odor. 4, in chronic nephritis or nephrotic syndrome stage, patients will appear no urine or some toxic substances, such as blood urea nitrogen, blood creatinine, etc., can not be eliminated from the body and retained in the blood will be emitted in the body smell of medicine, called ammonia odor. 5, if the bladder stones or have a bladder stone, or have a limited hyperhidrosis, fox odor will also have a bad body odor, If the patient has a bladder stone or an obvious colonic fistula, the feces in the intestine will enter the bladder through the fistula and will have a fecal odor.