The first morning urine smells bad, it may be a physiological phenomenon, but also may be the urinary system infection, endocrine diseases, kidney function abnormalities and other reasons. 1. Physiological phenomenon: due to personal dietary structure changes, or tobacco and alcohol stimulation of drinking water, less sweating, more causes such as concentrated urine, can also cause the first morning urine smell phenomenon, generally drink more water to adjust the dietary structure will be restored on its own. 2. Urinary tract infections: such as cystitis, urethritis, pyelonephritis and other diseases, may also cause urine abnormalities, resulting in the first bubble of urine smell, there may also be frequent urination, urinary urgency and other symptoms. 3. Endocrine diseases: for example, diabetes mellitus caused by glucose metabolism disorders, may cause glucose in the urine, thus causing the first urine smell and other symptoms. 4. Abnormal renal function: chronic glomerulonephritis, renal tumors, renal failure and other reasons, will affect the kidney’s filtration rate of urine, resulting in urine abnormalities, leading to the phenomenon of the first morning urine smell. The first morning urine smells bad, may also be caused by other reasons, you need to go to the regular hospital for examination, clear cause, follow the doctor’s instructions for treatment, and strive for early recovery.