Unusual body odors sometimes provide important clues about underlying health conditions. The human body can produce distinct smells when certain metabolic processes become disrupted. In many cases, these odors are mild and may result from lifestyle factors like diet or hygiene. However, persistent or especially strong odors might indicate a more serious condition. This article focuses on three possible health concerns—liver disease, kidney problems, and diabetes—and how each can alter your body’s natural scent.

Why Body Odor Changes

Your body relies on a delicate balance of enzymes, hormones, and chemical reactions to maintain good health. Various processes break down nutrients, excrete waste, and filter toxins. If something goes wrong with these processes, metabolic byproducts can build up and cause unusual smells. Smelling a fishy, ammonia-like, or sweet odor can hint at organ dysfunction or metabolic imbalances. These scent changes frequently appear first in your breath, sweat, or urine.

When such odors arise, it does not automatically confirm an illness. Some foods—especially spicy dishes, coffee, or garlic—can also change your scent. Medications, supplements, or temporary digestive issues can play a role. Still, if the odor persists or intensifies, it is best to investigate further.

Liver Problems and Musty or Fishy Smells

The liver serves as your body’s primary detoxifier. It filters your blood, metabolizes nutrients, stores vitamins, and helps break down harmful substances. When the liver malfunctions, toxins accumulate in the bloodstream. Some of these toxins can escape through your breath or sweat.

People with certain liver conditions sometimes develop a musty, fishy, or sweet smell in their breath. This odor arises from elevated levels of substances like dimethyl sulfide. The scent is often described as “musty” or “rotten,” and loved ones may notice it before the individual does. Chronic liver disease, cirrhosis, and advanced hepatitis are common causes.

Liver problems often reveal themselves through symptoms such as jaundice (yellowing of the skin or eyes), dark urine, pale stools, persistent fatigue, swelling in the legs or abdomen, and a tendency to bruise or bleed easily. If you suspect liver disease, early evaluation can prevent further damage.

Kidney Problems and Ammonia-Like Odors

Your kidneys remove waste products, excess water, and toxins from the blood. They also help regulate blood pressure, produce red blood cells, and control electrolyte balance. When the kidneys do not function properly, waste can build up, causing changes in bodily fluids.

Kidney dysfunction can cause an ammonia-like odor in the breath or sweat because the body struggles to clear urea and other nitrogen-based waste products. If you detect a strong urine-like scent that seems to come from your pores or your mouth, it may point to reduced kidney function.

Besides odor, kidney problems often present with swelling in the ankles or face (edema), changes in urination patterns or urine color, fatigue, muscle cramps, and persistent back or flank pain. If detected early, kidney disease can be managed or sometimes slowed.

Diabetes and Sweet or Fruity Breath

In diabetes, the body either does not produce enough insulin or cannot use insulin effectively. This causes elevated blood sugar levels, which can affect many organs. When cells cannot access glucose for energy, the body breaks down fats as an alternative. This produces acidic molecules called ketones.

A telltale sign of diabetic ketoacidosis (DKA)—a serious and potentially life-threatening complication of uncontrolled diabetes—is sweet or fruity-smelling breath. This scent, sometimes described as a “nail polish remover” odor, occurs from acetone, a type of ketone. If you notice this smell and also experience excessive thirst, frequent urination, nausea, and fatigue, you should see a healthcare professional as soon as possible.

Other classic symptoms of unmanaged diabetes include unexpected weight loss, blurred vision, and recurrent infections. Early diagnosis and proper treatment can lower the likelihood of serious complications such as nerve damage, heart disease, and kidney failure.

When to Seek Medical Attention

If you or someone close to you notices a persistent strange smell—be it musty, ammonia-like, sweet, or otherwise—do not ignore it. Many factors contribute to body odor, so rule out simple causes such as dietary changes or new medications. If the odor remains or becomes stronger, schedule an appointment with your healthcare provider.

Time is crucial in diagnosing and treating serious conditions. For instance, poor liver function can lead to life-threatening complications, while kidney disease can progress silently until advanced stages. Uncontrolled diabetes can severely damage blood vessels and nerves. Early intervention often yields better outcomes.

Steps in the Diagnostic Process

Medical History
Your doctor will review your symptoms, family history, lifestyle, and medications.
Physical Examination
They may check vital signs, perform a thorough physical exam, and evaluate specific problem areas such as the abdomen or flank region.
Laboratory Tests
Blood and urine tests can detect changes in organ function. For liver issues, your provider may order liver function tests (LFTs). For kidney problems, they might check creatinine, blood urea nitrogen (BUN), and estimated glomerular filtration rate (eGFR). If diabetes is suspected, tests like fasting blood glucose, hemoglobin A1C, and ketone levels can provide clarity.
Imaging
Ultrasound, CT scans, or MRI studies can help identify structural abnormalities in the liver or kidneys.
Additional Testing
In some cases, a liver biopsy or other specialized tests might be necessary.