# What Causes Smelly Urine? Doctors Explain 13 Possible Reasons
Urine odor changes for straightforward reasons most of the time. The most common culprit is dehydration. When you drink less water, urine becomes more concentrated, intensifying its smell. Increasing fluid intake typically resolves the issue within hours.
Dietary choices rank second. Asparagus contains sulfur compounds that metabolize into volatile substances, creating a distinctive sulfurous odor in urine. Garlic, onions, and certain spices produce similar effects. These smells vanish once your body processes and eliminates the foods.
Urinary tract infections (UTIs) cause noticeably foul-smelling urine alongside other symptoms like burning during urination and pelvic discomfort. UTIs require antibiotic treatment from a healthcare provider. Ignoring symptoms allows infections to worsen and potentially spread to the kidneys.
Diabetes presents another possibility. High blood sugar levels can produce fruity-smelling urine, a sign requiring medical evaluation. Phenylketonuria (PKU), a rare genetic condition affecting amino acid metabolism, creates a distinctive musty or mousy odor. Screening catches PKU in newborns, allowing early dietary management to prevent serious complications.
Medications including some antibiotics and B vitamins can alter urine odor. Liver disease, kidney dysfunction, and certain metabolic disorders also change smell patterns. Trimethylaminuria, an uncommon genetic condition, causes fish-like odor in urine and sweat due to impaired trimethylamine processing.
Most odor changes resolve without intervention. However, persistent foul smells, especially when accompanied by fever, cloudy appearance, or urgency, warrant medical attention. Your doctor can perform urinalysis and urine culture