Definition

Urine usually has a distinct odor, but under normal circumstances, the odor is relatively mild and not too noticeable. Certain conditions, however, may cause your urine to have an unusual or unpleasant odor, which may raise concerns about a problem or abnormality.

Causes

Urine consists mainly of water. It's the amount and concentration of various waste products excreted by the kidneys that causes urine odor.

Urine that contains a lot of water and few waste products has little to no odor. If urine becomes highly concentrated — a high level of waste products with little water — your urine may have a strong ammonia odor.

Some foods and medications, such as asparagus or certain vitamins, can cause a noticeable urine odor, even in low concentrations. Sometimes, unusual urine odor indicates a medical condition or disease, such as:

• Cystitis (bladder inflammation)
• Dehydration
• Diabetic ketoacidosis
• Gastrointestinal-bladder fistula (abnormal connection between the intestines and bladder)
• Maple syrup urine disease (rare genetic condition that becomes apparent during infancy)
• Metabolic disorder (a problem with the way your body converts the foods you eat into energy)
• Type 2 diabetes (uncontrolled)
• Urinary tract infection (UTI)

When to see a doctor

Most changes in urine odor are temporary and don't mean you have a serious illness, particularly if you have no other symptoms. When an unusual urine odor is caused by an underlying medical condition, other symptoms are also present. If you're concerned about the odor of your urine, talk to your doctor.