Alcohol intolerance test: Causes, symptoms, and methods

Sabina Muminović Last updated: 9 November 2023

Forget hangover – many people experience a nightmare of unpleasant effects even after a small amount of alcohol. In this article, we discuss alcohol intolerance causes, symptoms, and which tests you can do if you suspect you have it!

Punch or mulled wine to warm you up on a winter stroll through the city, gin tonics at the office party, and, of course, mandatory sparkling on the New Year’s Eve – no wonder alcohol consumption peaks in December!

While we should all drink in moderation, for some, even small amounts bring out skin rash, nausea, or headache.

A clear signal that they’re likely intolerant to alcohol!

Read on as we discuss what alcohol intolerance is, how it differs from alcohol allergy, how to test for it, and if it means you must completely cut out all alcohol.

In this article


What’s the difference between an intolerance and an allergy?
What causes alcohol intolerance?
How can your genes cause alcohol intolerance
Alcohol intolerance symptoms and when do they occur
Alcohol intolerance test: Which one to take?
DNA test
Clinical tests
#1 A skin prick test
#2 Blood test
#3 Ethanol patch test
Home “test”
What to do if you are alcohol intolerant?

What’s the difference between an intolerance and an allergy?

But first, we should clarify the difference between an intolerance and an allergy. A food or drink intolerance means either the body cannot properly digest a particular food or liquid, or that it might irritate the digestive system.

Symptoms of food or drink intolerance are uncomfortable and can make you feel ill, but are generally not very dangerous. They include nausea, gas, cramps, diarrhoea, and headaches.

You can discover if you’re genetically predisposed to alcohol intolerance with our DNA test! Click on the photo below to learn more.

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A food or drink allergy is a different story. It happens when the body’s immune system gets involved. It sees the food or liquid as a threat, and it responds by releasing chemicals like histamine – that’s what we call an allergic reaction.

Such a reaction can cause more serious or even life-threatening symptoms like breathing problems, throat tightness, vomiting, swelling, or a drop in blood pressure.

Fortunately, most people who have a reaction to alcohol aren’t allergic to it. They have alcohol intolerance. As you’ll see, the reasons behind it can be very different.

Woman suffering from stomach ache

What causes alcohol intolerance?

There are quite a few factors that appear to increase the likelihood of alcohol intolerance. Here are the most common ones:

  • enzyme deficiency,
  • asthma, Hodgkin’s lymphoma or damaged liver,
  • East Asian ancestry (more prone to enzyme deficiency),
  • sulfites,
  • various preservatives,
  • ethanol (increases gut permeability, allowing toxins and bacteria to pass into the bloodstream).

You may also have an inflammatory reaction to a certain ingredient in your alcoholic drink of choice. Most often, people are intolerant to:

  • grapes,
  • hops,
  • wheat, barley, rye, and grains,
  • yeast, which ferments the alcohol,
  • seafood, egg, or fruit proteins present in beverages,
  • histamines.

The different causes are important when you’re choosing your alcohol intolerance test and how to handle the symptoms.

To understand what exactly is happening in your body in some cases, especially when talking about an intolerance caused by enzyme efficiency, you should understand the role of your genes.

How can your genes cause alcohol intolerance

The reason for alcohol intolerance or slow metabolism of alcohol can be the following two genes:

ALDH1 gene: codes for the ADH1 enzyme, responsible for converting ethanol from alcohol into acetaldehyde, a substance even more toxic than ethanol.

An unfavourable variant increases ADH1 enzyme activity, leading to the build-up of acetaldehyde.

ALDH2 gene: codes the ALDH2 enzyme responsible for the breakdown of acetaldehyde.

An unfavourable variant leads to less active enzyme, which results in the accumulation of acetaldehyde and, consequently, alcohol intolerance.

Comparison of alcohol intolerance and allergy symptoms

Alcohol intolerance symptoms and when do they occur

If you’re intolerant to alcohol, you might experience certain signs and symptoms that occur after drinking. Note that alcohol intolerance doesn’t mean you’ll become intoxicated faster than others, but that you will have a negative and unpleasant reaction to alcohol.

Generally, you see symptoms occur shortly after consuming alcohol – in about 20 or 30 minutes. Symptoms can persist for one or two hours, but keep in mind that not everyone will experience alcohol intolerance in the same way and severity.

If you have alcohol intolerance, you may encounter one or several of these symptoms:

  • flushed face,
  • diarrhoea,
  • feeling hot,
  • headache,
  • dizziness,
  • heartburn,
  • hives (red bumps on your skin),
  • rashes,
  • faster heart rate or palpitations,
  • low blood pressure,
  • stuffy or runny nose,
  • stomach pain, which can lead to nausea or vomiting,
  • shortness of breath.

However, if you have an alcohol allergy, you can experience more serious symptoms and severe reactions. Pay attention to the following symptoms and be ready to call an ambulance if they suddenly get worse:

  • rashes,
  • swelling,
  • difficulty breathing,
  • throat tightness,
  • stomach cramps,
  • vomiting,
  • drop in blood pressure,
  • loss of consciousness,
  • anaphylaxis, which is a severe allergic reaction that can include a rapid, weak pulse, nausea, and vomiting. You should immediately call an ambulance.

And now, let’s see how you can determine what could be causing your intolerance.

Alcohol intolerance test: Which one to take?

DNA test

With a simple saliva-based test you order online and perform at home, you can determine if you carry the unfavourable variants of ALDH2 or ADH1 genes.

Our MyLifestyle DNA test analyses more than just alcohol metabolism; you can also discover your genetic likelihood of alcohol addiction as well as intolerance to caffeine, gluten, lactose, and more.

Clinical tests

Alternatively, you can visit your doctor and undergo one of the clinical tests. Your doctor will probably start by asking you questions about your symptoms and medical history, such as:

  • Which alcoholic beverages trigger your symptoms?
  • What symptoms do you experience?
  • When did you start getting symptoms?
  • Do you have a family history of allergies?
  • Do you have any other medical conditions?

Then they’ll decide which test will help them understand what it is that you’re intolerant to. It may be ethanol or it might be ingredients in certain drinks that are causing you discomfort.

Here are the 3 most common tests:

#1 A skin prick test

This is a physical exam where your doctor will use a lancet to prick or scratch your skin. They will apply a drop of an allergen extract to the pricked or scratched area.

Your skin’s reaction will let them determine whether you might have an allergy to something in alcoholic beverages — for example, the grains in beer. If you’re allergic to the substance being tested, you’ll develop a raised bump or a similar skin reaction.

#2 Blood test

This test measures your immune system’s response to a particular substance by checking the amount of immunoglobulin E antibodies in your bloodstream.

A blood sample is sent to a laboratory to check reactions to certain allergens. This test determines allergies and isn’t always accurate.

#3 Ethanol patch test

During this test, your doctor places a drop of ethanol on a gauze pad and tapes it to your arm, waits about seven minutes and then removes the gauze and checks for signs of redness, itching, or swelling. This can help them determine if you’re allergic to ethanol.

Home “test”

There’s also a test you can do at home on your own if you have only mild symptoms.

First, stop drinking all alcoholic beverages for at least a few days.

Then, try your go-to drinks one by one, separated by a day or two, and observe your reaction. That way, you’ll see if you’re only intolerant to certain drinks and might guess which ingredients cause the reaction.

You might also discover that you’re simply alcohol intolerant and have a reaction to anything that contains it.

Woman about to take a sip of red wine

What to do if you are alcohol intolerant?

If you have an alcohol allergy or are experiencing strong symptoms, you shouldn’t be drinking alcohol. Unfortunately, there’s no way around it, as even a small amount of alcohol can trigger a strong reaction.

If you don’t tolerate a specific ingredient in certain alcoholic products, you can drink beverages without it. Make sure that they don’t contain it, and you’re good to go. For example, you might not tolerate barley, which is often found in beer. But there’s no barley in red or white wine, so they shouldn’t cause a reaction.

If you’re experiencing mild symptoms but would still like to drink a glass or two, there are certain measures that can help you alleviate the reaction.

  1. Drink slower to give your body more time to prevent acetaldehyde buildup.
  2. Mix or dilute with non-alcoholic beverages.
  3. Drink plenty of water as it helps to eliminate alcohol and its metabolites from your body.

Now you know what causes alcohol intolerance, what symptoms to observe, and what are different alcohol intolerance test options.

Even if you’re not alcohol intolerant, always remember to drink responsibly and don’t take any unnecessary health risks!


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