There is a smell of ammonia in urine, possible causes: First, when you hold urine for a long time or in a state of urinary retention, the urine that is guided out will smell like ammonia. Because urine is stored in the bladder for too long, ammonia is produced by the decomposition of microproteins in the urine, and then the urine discharged will smell like ammonia. After drinking more water and urinating properly, this situation can be improved. Second, the urine of long-term high-protein diet or meat diet is acidic, while the content of microprotein can be increased, which can cause increased protein decomposition, there will be the smell of ammonia. Adjust the diet structure, reduce the protein intake, etc., the smell in the urine can be improved. Third, if there is a urinary tract infection, there are bacteria in the urine, bacteria are prone to decompose the protein and other substances in the urine, resulting in volatile ammonia, which can cause the smell of ammonia in the urine. At the same time, it can be accompanied by frequent urination, urgent urination, painful urination, cloudy urine and yellowish color, which requires a urine culture test to further confirm the diagnosis.