What causes urine odor?

Urine odor may be described as foul, strong, musty, sweet, or as smelling like sulfur or ammonia. Urine odor may be caused by conditions that are not harmful (benign) or by mild to serious diseases and disorders.

Benign causes of urine odor

Urine odor may be caused by a variety of conditions that are not harmful or not caused by disease including:

  • Eating certain foods, such as garlic, onions, fish and asparagus. Asparagus can cause a sulfur-like smell of the urine. The unusual odor should go away after these foods have been digested.

  • Taking vitamins and certain medications can cause an unusual urine odor as a side effect.

Potentially harmful causes of urine odor

Urine odor may be caused by infection, inflammation, or other conditions of the urinary tract (kidneys, ureters, bladder and urethra) or the reproductive organs. Urine odor can also be caused by diseases that affect the urinary tract as well as other organs and body systems.

Causes of urine odor related to the urinary tract include:

  • Cystitis (bladder inflammation or infection), which can produce a foul urine odor

  • Prostatitis (inflammation or infection of the prostate gland)

  • Urinary tract infection, such as a bladder infection or kidney infection (pyelonephritis), which can produce a foul urine odor

Urine odor can be caused by other diseases and conditions including:

  • Dehydration, which can produce an ammonia-like urine odor

  • Liver failure, which can produce a musty urine odor

  • Maple syrup urine disease, which produces a sweet, caramel-like urine odor

  • Rectal fistula, an abnormal opening or connection between the rectum and other areas of the body

  • Untreated or poorly treated diabetes, which produces a sweet or sugary urine odor

What are the potential complications of urine odor?

Complications associated with urine odor vary depending on the underlying disease, disorder or condition. Complications of untreated or poorly controlled diseases, such as diabetes and liver failure, can be serious and even life threatening. Over time, underlying causes of urine odor can lead to serious complications including:

  • Diabetic coma

  • Electrolyte imbalance

  • Ketoacidosis

  • Septicemia (a blood infection)

  • Severe dehydration

  • Shock

  • Urosepsis (severe urinary tract infection that has spread and led to systemic inflammation called sepsis)


  1. Urine Odor. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/007298.htm.
  2. Urinary Tract Infection – Adults. PubMed Health, a service of the NLM from the NIH. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001549.

What is urine odor?

Healthy urine may have a mild smell but generally does not have a foul odor. In some cases, an unusual or strong urine odor may be due to benign conditions that are not harmful, such as eating certain foods or taking certain medications. When urine persistently smells bad or has a foul, strong or unusual odor, it may be caused by an underlying disease, disorder or condition.

... Read more about urine odorintroduction


What other symptoms might occur with urine odor?

Urine odor may be accompanied by other symptoms, which vary depending on the underlying disease, disorder or condition. Symptoms can be due to problems in the urinary tract (kidneys, ureters, bladder and urethra), the reproductive system, the endocrine system, the cardiovascular system, and other organs and systems of the body.

Urinary tract symptoms that may occur with urine ... Read more about urine odorsymptoms

Medical Reviewer: Cynthia Haines, MD Last Annual Review Date: Aug 11, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Kidneys and the Urinary System

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