The smell of ammonia in urine is a possible cause: first, urinary retention or prolonged urine holding, urine concentration can cause the decomposition of protein in urine, which can produce ammonia-like substances, so the smell of ammonia will appear when urinating. At the same time can be accompanied by yellow urine, but generally not accompanied by frequent urination, urinary urgency, painful urination, appropriate more water or timely urination, this situation can disappear. Secondly, if there is kidney disease and there is more protein in the urine, the smell of ammonia can appear. Third, if there is a urinary tract infection, the bacteria in the urine can decompose the components in the urine and form ammonia, which can cause the smell of ammonia in the urine. It is usually accompanied by symptoms such as frequent urination, urinary urgency, and painful urination, and requires routine urine examination to further rule out the presence of infection. Fourth, long-term use of meat or high-protein diet, the smell of ammonia in the urine can also appear, control the diet with reasonable or reduce the protein diet, the smell of ammonia in the urine can gradually disappear.