Alcohol intolerance is a real condition that may occur suddenly or later in life. Here’s why your body may start to reject drinking alcohol.

If you have a pattern of suddenly feeling very sick after consuming alcohol, you may have developed sudden onset alcohol intolerance. Your body may also start to reject alcohol later in life because as you age and your body changes, the way you respond to alcohol can also change.

Article at a Glance:

  • Having an alcohol intolerance is a genetic condition that means your body cannot process alcohol easily.
  • Symptoms of an alcohol intolerance most often develop rapidly, immediately following having a drink, and can result in mild to severe side effects.
  • Alcohol intolerance is often confused with other health conditions that produce similar side effects like having an alcohol allergy.
  • You are at higher risk for alcohol intolerance if you are of East Asian descent. As a genetic condition, therefore, it is likely that your family members are at risk.
  • There is no treatment for alcohol intolerance at this time, other than avoiding alcohol.

What Is Alcohol Intolerance?

Alcohol intolerance is a real condition, but it can sometimes be confused with other related conditions, such as allergies or drug interactions with alcohol. Having an alcohol intolerance is a genetic condition that means your body cannot process alcohol correctly.

What Are the Symptoms of Alcohol Intolerance?

Symptoms of alcohol intolerance most often develop rapidly. Sometimes, they can occur immediately following drinking alcohol. Symptoms can be mild or severe and may include:

  • Flushed skin, redness or rashes
  • Nausea and vomiting
  • Fast heartbeat
  • Low blood pressure
  • Headaches
  • Feeling very tired
  • A runny or stuffy nose
  • Worsening asthma symptoms

For mild intolerances, you should either avoid alcohol, limit how much you drink or avoid certain types of alcohol with ingredients that may cause a reaction. However, if you have a serious allergy-like reaction following drinking alcohol, consult a medical professional.

Alcohol Allergy vs. Alcohol Intolerance

People often mistake alcohol allergies for alcohol intolerance. Alcohol intolerance is a rare condition in which your body cannot process alcohol correctly, leading to a build-up of a chemical called acetaldehyde. High levels of acetaldehyde are what cause the unpleasant symptoms of alcohol intolerance. 

An allergy to alcohol has a very different cause from alcohol intolerance. Someone with an alcohol allergy has an allergic reaction when exposed to alcohol or to a component of alcohol. Often, it is not actually an allergy to alcohol itself but to a component of the alcohol, like grapes or hops. The symptoms are caused because the body’s immune system becomes overactive and attacks something found in the alcohol.  

Symptoms of an Alcohol Allergy

An alcohol allergy creates symptoms because the immune system becomes overactive. Symptoms of an alcohol allergy can range from mild to severe and may include:

  • Runny nose
  • Coughing
  • Wheezing
  • Itchy, raised welts (hives)
  • Swelling of the face, mouth or tongue
  • Nausea and vomiting
  • Diarrhea
  • Lightheadedness

Allergy symptoms that affect breathing or have the potential to block your airway, such as swelling in the mouth or of the tongue, can be life-threatening. If you have any of these symptoms or you are with someone who does, you should immediately seek emergency help by calling 911.

Why Can I No Longer Tolerate Alcohol?

Even if you know alcohol makes you feel poorly, it can sometimes be hard to figure out the root cause of the problem. Symptoms may be caused by a few different conditions. The main cause of alcohol intolerance is a problem with how the body breaks down alcohol.

What Can Cause an Alcohol Intolerance?

Having an alcohol intolerance is a genetic condition that means your body can’t process alcohol easily. With this condition, you have an inactive or less-active form of the chemical that breaks down alcohol in your body.

When you drink alcohol, your liver first breaks down alcohol into a toxic chemical called acetaldehyde. Your body uses an enzyme called aldehyde dehydrogenase, or ALDH2, to break down acetaldehyde. When broken down, acetaldehyde does not affect you. However, in some people, ALDH2 does not work correctly, resulting in alcohol intolerance.

Doctors have found that a problem with ALDH2 (the enzyme that helps break down the byproduct of alcohol) is genetic. Therefore, it is likely that your family members are at risk for the same problem. The main risk factor for having a problem with ALDH2 is being of East Asian descent, especially Chinese, Korean or Japanese.

Why Am I Developing Alcohol Sensitivity?

  • Alcohol Allergy – An allergy to alcohol itself is very rare, as the body naturally produces small amounts of alcohol on its own. A true alcohol allergy is triggered by very minimal amounts of ethanol. It’s more likely that you have an allergy to a specific ingredient in your drink. Alcoholic drinks may contain allergens, which can range from wheat to egg proteins. Allergens in your drink may be the cause of your symptoms. You may be able to drink alcohol if you can avoid the specific ingredient that makes you feel unwell.
  • Medication Interacting with Alcohol – Some prescriptions advise against consuming alcohol alongside the medicine to avoid intensifying the effects of the substances. Therefore, several drugs may make you feel very sick when taken with alcohol. Speak to your doctor or pharmacist to make sure that your drugs are safe to take with alcohol.
  • Alcohol Sensitivity & Age –  Alcohol sensitivity can develop with age. Older adults tend to get drunk quicker than younger adults because their alcohol tolerance decreases. The reason for this decrease is due to a couple of natural changes the body goes through:
    • Higher Body Fat Percentage: As you age, you lose muscle and water and gain body fat. A higher blood alcohol level when you drink is the result of this change in your body’s composition.
    • Changes in Liver Health: Liver functionality declines with age. The liver is unable to break down alcohol as fast as it could when you were younger. Therefore, alcohol stays in your system longer than it used to.

Alcohol Intolerance Treatment

Even if you only have mild symptoms of alcohol intolerance, you should avoid alcohol. Research has shown that some people with mild symptoms of intolerance can get used to the symptoms of excess acetaldehyde in their bodies. However, acetaldehyde is still highly toxic and can significantly increase the risk of cancer.

Unfortunately, the only treatment for alcohol intolerance is avoiding alcohol. No drug will help you avoid the symptoms of alcohol intolerance or lessen your cancer risk.

a man sitting on a bed with his head in his hands.
Can I Detox From Alcohol At Home?

Alcohol detox isn’t easy and not everyone can do it on their own. That is why alcohol detox and alcohol withdrawal treatment is administered by medical professionals.

a person holding a glass of beer on a couch.
Am I An Alcoholic?

Alcoholism takes many forms, and the stereotype doesn’t always hold true. So when do a few drinks with friends become a full-blown alcohol addiction? How do you know if you are an alcoholic?

a woman holding her stomach in front of her stomach.
Repairing Liver Damage From Alcohol Use

While cirrhosis scars from excessive drinking are irreversible, quitting alcohol and leading a healthier lifestyle can help your liver heal from alcohol-related liver disease.

a table topped with fruits and vegetables next to juice.
Foods to Eat When Detoxing From Alcohol

When detoxing, hydration is key. However, certain food groups also have benefits when it comes to helping with the discomfort of withdrawal symptoms and detoxification.

a white alarm clock sitting on top of a wooden table.
How Long Does Alcohol Detox & Withdrawal Take?

Detox from alcohol can begin within hours. Typically, alcohol withdrawal symptoms happen for heavier drinkers. Alcohol withdrawal can begin within hours of ending a drinking session.

a group of people holding glasses of beer.
What Are the Effects of Daily Drinking?

Daily drinking can have serious consequences for a person’s health, both in the short- and long-term. Many of the effects of drinking every day can be reversed through early intervention.

a woman with long brown hair smiling at the camera.
Editor – Abby Doty
Abby Doty graduated from Hamline University in 2021 with a Bachelor's in English and Psychology. She has written and edited creative and literary work as well as academic pieces focused primarily on psychology and mental health. Read more
a man with a beard wearing a suit and tie.
Medically Reviewed By – Benjamin Caleb Williams, RN
Benjamin Caleb Williams is a board-certified Emergency Nurse with several years of clinical experience, including supervisory roles within the ICU and ER settings. Read more

National Institute on Alcohol Abuse and Alcoholism. “Alcohol “Flush” Signals Increased Ca[…]g East Asians.” March 23, 2009. Accessed August 30, 2022.

National Institute on Alcohol Abuse and Alcoholism. “Older Adults”>Older Adults.” Accessed August 30, 2022.

Baptist Health. “Alcohol Allergy”>.” 2022. Accessed August 30, 2022.

Wall, Tamara L.; Ehlers, Cindy L. “Genetic Influences Affecting Alcohol Use[…]Among Asians.” Alcohol Health and Research World, 1995. Accessed August 30, 2022.

Genetic and Rare Diseases Information Center. “Acute alcohol sensitivity.”>” National Center for Advancing Translational Sciences, November 8, 2021. Accessed August 30, 2022. 

Ehlers, I.; Hipler, U-C; Zuberbier, T.; Worm, M. “Ethanol as a cause of hypersensitivit[…]ic beverages.” Clinical & Experimental Allergy, August 2002. Accessed August 30, 2022. 

Ramapo College of New Jersey. “ALCOHOL ALLERGIES: DO THEY EXIST?”>ALCOHOL […]O THEY EXIST?” Accessed August 30, 2022.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.