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What Is Alcohol Intolerance?

What Is Alcohol Intolerance?
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Published on April 16, 2025
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If your skin starts to flush and redden and your nose becomes stuffy after you drink alcohol, you might have alcohol intolerance.

Alcohol intolerance is a genetic condition in which the body can’t break down alcohol efficiently, leading to immediate, uncomfortable reactions after drinking.

While there’s no cure for this inherited condition, you can prevent its unpleasant symptoms by avoiding alcohol.

Graphic titled, how alcohol intolerance affects the body. Illustrated points include facial flushing and redness, stuffy or runny nose, throbbing headache, rapid heartbeat, low blood pressure, worsening asthma, diarrhea, nausea and vomiting, and heart
Alcohol intolerance can cause any or all these symptoms in a person with the condition.Everyday Health

Signs and Symptoms of Alcohol Intolerance

The hallmark signs and symptoms of alcohol intolerance include:

  • Flushing and redness on the face, neck, and chest
  • Stuffy or runny nose
  • Nausea and vomiting
  • Low blood pressure (hypotension)
  • Diarrhea
  • Heart palpitations or rapid heartbeat (tachycardia)
  • Throbbing headache
  • Worsening asthma

Causes and Risk Factors of Alcohol Intolerance

Alcohol intolerance is caused by a genetic mutation of an enzyme that metabolizes alcohol, called aldehyde dehydrogenase 2 (ALDH2). The alteration of ALDH2 makes the enzyme inactive or less active, inhibiting your body’s ability to break down alcohol once you drink it.

Some people are more likely to have an alcohol intolerance than others. They include:

  • People of East Asian Descent Researchers estimate about 36 to 45 percent of people from East Asian countries, including Japan, China, Korea, and Taiwan, have an alcohol intolerance. Some researchers refer to this phenomenon as “Asian flush.”

  • People With Chronic Fatigue Syndrome Some researchers suggest that those diagnosed with myalgic encephalomyelitis chronic fatigue syndrome (ME/CFS) may be more likely to experience alcohol intolerance than the general population. It’s important to note, though, that studies on the link between ME/CFS and alcohol intolerance have had mixed findings, and more research is needed to explore the link between the two.

  • People With Long COVID Anecdotal reports of people with post-acute COVID-19 syndrome (PACS), also known as long COVID, having new or heightened alcohol sensitivities prompted researchers to study the link between long COVID and alcohol intolerance. While it’s still unclear why some with long COVID experience a lower tolerance for alcohol, limited research suggests it could be due to changes in prostaglandin levels (substances in the body that affect functions like inflammation) or the gut microbiome (gut bacteria) post-COVID.

  • People With Hodgkin Lymphoma Alcohol intolerance is a potential symptom of Hodgkin lymphoma, a type of cancer.

How Is Alcohol Intolerance Diagnosed?

Most people will know if they’re alcohol intolerant based on the symptoms that develop after they have a drink, namely flushing and congestion.

Beyond the symptomatic response, certain tests like the ethanol patch test can help diagnose an alcohol intolerance. During this test, a provider will drop ethanol onto a gauze pad or cotton pad and tape it to your arm. After waiting seven minutes, they’ll remove the material to check for signs of redness, itching, or swelling, which could indicate an alcohol intolerance.

Treatment and Medication Options for Alcohol Intolerance

There are no treatment options for alcohol intolerance because it’s an inherited, genetic condition. Your best bet to avoid symptoms is to avoid drinking altogether.

Some people with alcohol intolerance take over-the-counter antihistamines and antacids to help with minor symptoms. But because these medications only mask the symptoms rather than treat them, you may end up drinking more than you realize, which will only worsen the problem.

Prevention of Alcohol Intolerance

Alcohol intolerance is a genetic condition, so it cannot be cured or treated. People who have alcohol intolerance can only keep symptoms away by avoiding alcohol altogether. You should also be mindful of mixing alcohol with medications that bear a warning label against the combination, because this can make alcohol intolerance symptoms even worse.

Alcohol Intolerance Prognosis

As mentioned, alcohol intolerance is a genetic condition, meaning it’s lifelong. You can avoid symptoms by not drinking alcohol.

Complications of Alcohol Intolerance

Alcohol intolerance can cause minor symptoms, such as flushing and redness, but it can also lead to more serious problems over time if someone with the condition continues to drink.

 Complications can include:
  • Increased risk of cancer: Researchers say people with the ALDH2 gene who keep drinking are at a higher risk of developing cancer — specifically esophageal cancer, liver cancer, and oral cancers. Scientists urge people with the hallmark symptom of flushing to pay attention to this symptom because it’s an indicator of increased genetic risk for cancer.

  • Increased risk of heart disease: Researchers have also linked the ALDH2 gene to coronary artery disease, suggesting the enzyme deficiency tied to this gene mutation causes damage in the cells that line the inside of blood vessels.

Research and Statistics: How Many People Have Alcohol Intolerance?

It’s estimated that about 8 percent of the global population carry the ALDH2 variant, making them intolerant of alcohol.

 But the rates increase dramatically for people of Chinese, Japanese, or Korean descent. As mentioned, researchers estimate that between 28 and 54 percent of people of East Asian descent have alcohol intolerance.

Related Conditions: Alcohol Allergy

One condition that many people confuse with alcohol intolerance is alcohol allergy. While the two have some overlapping symptoms, there are key differences between them.

As mentioned, alcohol intolerance is a genetic condition that prevents the body from processing alcohol efficiently. But an alcohol allergy is a response from the body’s immune system to specific ingredients in alcoholic drinks, such as grains, preservatives like sulfites, or other chemicals. If you’re allergic to any of these ingredients, your body produces antibodies in response to the allergen. This is called an allergic reaction.

While both can cause symptoms like runny nose, they have several differing symptoms. For instance, a telltale symptom that’s exclusive to alcohol intolerance is flushing and redness on the chest, neck, and face. On the other hand, alcohol allergies cause symptoms like itchy rashes, swelling, and intense stomach cramps.

If you’re not sure if you have alcohol intolerance or an alcohol allergy, talk to your doctor. They can help you figure out if you have either of these conditions or refer you to an allergist for testing.

The Takeaway

  • Alcohol intolerance is a genetic condition that inhibits the body’s ability to metabolize alcohol, causing immediate symptoms like skin redness or flushing and a stuffy nose.
  • Alcohol intolerance is most common in people of East Asian descent, though it can impact anyone.
  • There’s a difference between a true genetic intolerance of alcohol (caused by the ALDH2 genetic mutation) and someone who may be allergic to one or more ingredients in alcohol.
  • The only way to prevent the symptoms of alcohol intolerance is to avoid drinking alcohol. Doing so may prevent complications such as cancer and heart disease.

Common Questions & Answers

What is alcohol intolerance?
Alcohol intolerance is a genetic condition caused by the ALDH2 genetic variant that makes it difficult to metabolize alcohol. This leads to uncomfortable symptoms like skin flushing and congestion immediately after drinking.
There are telltale signs of alcohol intolerance that happen immediately after drinking alcohol, including skin redness or flushing, a stuffy nose, nausea or vomiting, a racing heartbeat, or diarrhea.
Because it’s a genetic condition, alcohol intolerance cannot be treated. The best way to prevent the onset of symptoms is to avoid alcohol altogether.
You can test for alcohol intolerance by working with a doctor who may administer a skin patch test or recommend genetic testing.

Resources We Trust

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Alcohol Intolerance: Symptoms and Causes. Mayo Clinic. April 6, 2023.
  2. Alcohol Intolerance. Cleveland Clinic. August 24, 2020.
  3. Jeon S et al. The alcohol flushing response is associated with the risk of depression. Scientific Reports. July 22, 2022.
  4. Moh I et al. The Alcohol Flush Response. Graphic Medicine Review. February 22, 2024.
  5. Maciuch J et al. Alcohol intolerance and myalgic encephalomyelitis/chronic fatigue syndrome. World Journal of Neurology. May 31, 2023.
  6. Eastin EF et al. New Alcohol Sensitivity in Patients With Post-acute Sequelae of SARS-CoV-2 (PASC): A Case Series. Cureus. December 29, 2023.
  7. Hoppe RT et al. Hodgkin Lymphoma, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology. Journal of the National Comprehensive Cancer Network. June 2020.
  8. Chen C et al. ALDH2 variance in disease and populations. Disease Models & Mechanisms. June 24, 2022.
  9. Alcohol Flush Signals Increased Cancer Risk among East Asians. National Institutes of Health.
  10. Ng CS et al. ALDH2 polymorphism, alcohol intake and the attributable burden of cancer in East Asia: systematic review, meta-analysis, and modeling study. Annals of Epidemiology. September 2023.
  11. Guo H et al. SGLT2 inhibitor ameliorates endothelial dysfunction associated with the common ALDH2 alcohol flushing variant. Science Translational Medicine. January 25, 2023.
  12. Yook HJ et al. Epidemiologic relationship between alcohol flushing and smoking in the Korean population: the Korea National Health and Nutrition Examination Survey. Scientific Reports. July 8, 2024.
  13. Alcohol Intolerance: What You Need to Know. Cedars-Sinai. November 3, 2023.
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Joy Tanaka, PhD

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Joy Tanaka, PhD, specializes in clinical molecular genetics. She is dedicated to integrating excellent clinical care with cutting-edge medical research for patients with rare and undiagnosed disorders, and is focused on pursuing questions at the interface between genetics and human disease with the goal of developing novel therapies and treatments.

Dr. Tanaka received her PhD from Yale University School of Medicine, where she was a Howard Hughes Medical Institute Medical Research Scholar and recipient of the George Robert Pfeiffer Fellowship for Translational Medicine. She completed her clinical fellowship in cytogenetics and clinical molecular genetics at Columbia University and New York Presbyterian Hospital, and is currently associate clinical laboratory director at Rady Children's Hospital Institute for Genomic Medicine in San Diego, California.

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