What is the condition that makes you smell like alcohol?

September 22, 2025 •

4 min read

According to reports, auto-brewery syndrome is an extremely rare but legitimate medical condition that makes you smell like alcohol without drinking it. This surprising phenomenon, often mistaken for regular alcohol intoxication, is caused by an overgrowth of fermenting organisms in the digestive system.

Quick Summary

The condition that can make you smell like alcohol without consuming it is called auto-brewery syndrome (ABS), or gut fermentation syndrome, where an overgrowth of yeast or bacteria in the gut ferments carbohydrates into ethanol. Other potential causes include diabetic ketoacidosis, liver disease, and specific metabolic conditions.

Key Points

Auto-Brewery Syndrome: The primary condition causing an alcohol smell without drinking, where gut microbes ferment carbs into ethanol.
Rare but Real: Although rare, auto-brewery syndrome is a legitimate medical condition that is often underdiagnosed and misunderstood.
Multiple Causes: Besides ABS, other conditions like diabetic ketoacidosis and liver disease can cause distinctive, sometimes alcohol-like, body odors.
Diagnosis is Key: Confirming ABS requires a specific carbohydrate challenge test, often after ruling out other potential causes.
Dietary Management: A low-carb, low-sugar diet is a cornerstone of managing ABS, as it removes the fuel for internal fermentation.
Treatment Options: Medical treatment for ABS includes antifungal or antibiotic therapy to address the gut microbe overgrowth.
Social Impact: Living with ABS can be challenging, leading to false accusations of alcohol use and legal complications, such as DUIs.

Understanding Auto-Brewery Syndrome (ABS)

Auto-brewery syndrome is a rare and often misunderstood condition in which the body internally ferments carbohydrates into ethanol, causing a person to feel and appear intoxicated without drinking alcohol. The fermentation is caused by an overgrowth of microorganisms—typically yeast like Saccharomyces cerevisiae (brewer's yeast) or species of Candida—within the gastrointestinal (GI) tract. This internally produced alcohol enters the bloodstream, resulting in symptoms similar to those of alcohol intoxication, including an alcoholic smell on the breath and from the skin.

The Mechanism of Internal Fermentation

The human digestive system hosts a diverse community of microorganisms, known as the gut microbiome. In individuals with ABS, this microbiome is unbalanced, allowing certain yeasts or bacteria to become dominant. When a person with ABS consumes carbohydrates and sugars, these microbes ferment them into ethanol, just like in the production of beer. The body's liver is then unable to process all of the internally brewed alcohol, leading to an accumulation in the blood and the characteristic symptoms of intoxication.

Symptoms and Social Impact

The symptoms of ABS are consistent with a state of being drunk and can severely impact a person's life, leading to significant social and legal problems. Sufferers may face accusations of lying about their sobriety, which can strain relationships and even lead to job loss or false DUI charges.

Common symptoms include:

Unexplained episodes of intoxication, dizziness, and disorientation
Slurred speech and impaired coordination
Fatigue and chronic fatigue syndrome
Gastrointestinal distress, including bloating and irritable bowel syndrome
Headaches and brain fog
Unpleasant body odor and bad breath smelling of alcohol

Other Medical Causes for an Alcohol-Like Odor

While ABS is the most direct cause of a person smelling like alcohol without drinking, other medical conditions can also produce similar smells, though they are often described differently. It is critical to consult a healthcare professional to determine the correct diagnosis.

Diabetic Ketoacidosis (DKA)

Diabetic ketoacidosis is a severe complication of diabetes that occurs when the body produces high levels of blood acids called ketones. This happens when there is not enough insulin to move glucose into the body's cells, so the body begins to burn fat for energy instead. The high level of ketones in the blood can give the breath a distinct, often described as fruity or nail polish remover-like, smell. While not a true alcohol smell, it is a metabolic byproduct that can be confused with one.

Fetor Hepaticus (Liver Disease)

This condition refers to a type of chronic bad breath caused by severe liver disease, specifically liver failure or decompensated cirrhosis. It occurs because the failing liver cannot properly filter toxic substances from the blood. These substances then build up and are released through the lungs, causing a distinct, musty, and sometimes garlicky or rotten egg-like odor on the breath.

Comparison of Conditions Causing Unusual Odors


Feature	Auto-Brewery Syndrome (ABS)	Diabetic Ketoacidosis (DKA)	Fetor Hepaticus (Liver Disease)
Core Cause	Overgrowth of fermenting microorganisms in the gut	Lack of insulin leading to high blood ketones	Liver failure; inability to filter toxins
Characteristic Smell	True alcohol/ethanol odor on breath and sweat	Fruity or acetone-like odor on the breath	Musty, sweet, or garlic-like breath odor
Trigger	High-carbohydrate or sugary diet	Untreated diabetes, illness, or malnutrition	Chronic, severe liver disease
Other Key Symptoms	Intoxication symptoms (dizziness, slurred speech)	Excessive thirst, urination, confusion, vomiting	Jaundice, abdominal swelling, confusion
Underlying Conditions	Antibiotic use, Crohn's, SIBO, diabetes	Type 1 or Type 2 diabetes	Cirrhosis, portal hypertension

Diagnosing and Treating Auto-Brewery Syndrome

Diagnosing ABS is challenging due to its rarity and the social stigma associated with it. The process typically involves ruling out other conditions and performing specific tests.

Medical History and Physical Exam: A doctor will take a comprehensive history, often with input from family members, to rule out deliberate alcohol intake.
Blood and Stool Tests: Lab tests can check for elevated blood alcohol levels and identify an overgrowth of fermenting yeast or bacteria through stool cultures.
Carbohydrate Challenge Test: This is the most definitive test. After a period of fasting, a patient is given a dose of glucose, and their blood alcohol content is monitored over several hours. A significant increase confirms the diagnosis.

Treatment focuses on restoring the balance of the gut microbiome and includes:

Antifungal or Antibiotic Therapy: Medications are used to eliminate the overgrowth of pathogenic yeast or bacteria.
Strict Dietary Changes: A low-carbohydrate, low-sugar diet is essential to deprive the fermenting microbes of their food source.
Probiotics and Supplements: Multi-strain probiotic supplements can help re-establish a healthy gut flora.

When to Seek Medical Attention

If you or someone you know consistently smells of alcohol without drinking, especially alongside other symptoms of intoxication, it is crucial to seek professional medical advice. The condition, if left untreated, can have serious long-term consequences, including liver damage and neurological issues. A proper diagnosis allows for appropriate treatment and can provide immense relief to those unfairly judged for their condition. Consulting a healthcare provider is the first and most important step towards management and recovery. For more in-depth medical information on this subject, refer to the StatPearls resource on Auto-Brewery Syndrome available through the National Institutes of Health: Auto-Brewery Syndrome - StatPearls.

The Path to Management and Recovery

Living with a rare condition like auto-brewery syndrome requires ongoing management, including strict dietary adherence and regular follow-ups with a medical team. The support of family and friends is also critical in navigating the social and emotional challenges that can arise from this unusual ailment.

Frequently Asked Questions

Auto-brewery syndrome, also known as gut fermentation syndrome, is a rare medical condition where the body internally produces alcohol. This happens when an overgrowth of yeast or bacteria in the gut ferments carbohydrates into ethanol.

Diabetic ketoacidosis (DKA) can cause a distinctive breath odor, often described as fruity or like nail polish remover, due to high levels of ketones. This smell is not the same as alcohol, but it can sometimes be mistaken for it.

Diagnosis typically involves a doctor conducting a carbohydrate challenge test. After fasting, you consume a glucose solution, and your blood and breath alcohol levels are monitored. An increase in alcohol levels confirms the diagnosis.

Yes, other conditions can cause distinct breath odors. For example, fetor hepaticus, a symptom of liver disease, can cause a musty or sweet-smelling breath, while kidney failure can cause an ammonia-like smell.

Yes, ABS is treatable. Management often involves a combination of antifungal medication, a strict low-carbohydrate diet to reduce fermentation, and sometimes probiotics to help rebalance gut flora.

Yes, what you eat can significantly affect your body odor. For someone with auto-brewery syndrome, consuming high amounts of carbohydrates and sugars can trigger the internal fermentation process and worsen symptoms.

In some cases, individuals with undiagnosed auto-brewery syndrome have failed breathalyzer tests and been charged with DUI. However, a proper medical diagnosis can be used in a legal defense, as it demonstrates that the alcohol was endogenously produced, not consumed.