The smell of urine is too heavy and unpleasant may be a physiological phenomenon, but also may be a symptom of certain diseases, such as urinary tract infections and diabetes. 1. Physiological phenomenon: when the occurrence of holding urine, due to the urine in the bladder storage for too long, the bacterial decomposition of excessive metabolites, can appear in the phenomenon of very smelly urine. 2. Urinary tract infection: refers to the bacterial reproduction in the urethra caused by the urine mixed with inflammatory secretions, which can lead to very smelly urine. Urinary tract infections also appear frequent urination, urinary urgency, urinary pain and other symptoms. 3. diabetes: patients with excessive sugar in the urine can be bacteria, through the oxidative decomposition of substances containing odor, there may be urine odor is too heavy phenomenon. Diabetes will also have symptoms of polyuria, excessive drinking, excessive eating, and weight loss. To summarize, the smell of urine is too heavy and unpleasant may also be caused by other reasons, and you should seek medical treatment in time.