Possible causes of very smelly urine: first, suffering from infections of the urinary tract, such as kidney abscess, pyelonephritis or cystitis, can appear very smelly urine, which can be accompanied by frequent urination, urinary urgency, painful urination, or accompanied by cloudy urine. Urine culture examination and routine urine examination are needed to identify. Second, when urinary retention occurs, or when urine is concentrated due to less drinking and more sweating, very smelly urine can occur. It is usually not accompanied by symptoms such as painful urination, but is accompanied by changes such as yellowish urine color, or dark brown color. Third, when the diet contains more special smelling foods, it can cause a transient change in urine. Such as eating a lot of onion, garlic, durian, etc. can appear briefly urine smelly phenomenon, after stopping the relevant food, this smell can disappear. Fourthly, if there is a fungal infection, the urine can smell very bad, such as patients with diabetes or patients who have been taking a lot of antibacterial agents and immunosuppressants for a long time, the urine can appear more smelly, and urine culture can find that there is a fungal infection in the urine.