Signs Your Hangover May Be Alcohol Intolerance

Have you ever found yourself dreadfully hungover after just one drink? Maybe you underestimated how much wine was in that big wine glass at the party last night? Perhaps you didn’t remember how those chemical compounds — congeners — in the cabernet always hit you so hard? Or maybe you don’t have a hangover at all but something else, like alcohol intolerance?

Alcohol intolerance and hangovers have many overlapping symptoms, which can make it challenging to identify the cause of our misery. Let’s dive into the differences.

Understanding Alcohol Intolerance

Alcohol intolerance is a condition marked by the impaired ability to break down and metabolize the toxins found in alcohol. Alcohol intolerance is caused by a mutation of the genes involving the enzymes that metabolize alcohol. This is not to be confused with low alcohol tolerance, in which case we still have normal enzymes for metabolizing alcohol but feel the effects of it after drinking a very small amount.

The normal alcohol metabolization process goes as follows: 

• An enzyme called alcohol dehydrogenase (ADH) breaks down ethanol (alcohol) into acetaldehyde (a compound toxic to our body).
• Aldehyde dehydrogenase (ALDH) converts acetaldehyde into acetate. 
• Acetate then gets further broken down into water and carbon dioxide to be eliminated. 

For those of us with alcohol intolerance, the enzymes ADH and ALDH are less active, making it difficult for our body to get rid of toxins from alcohol. This leads to a buildup of acetaldehyde, which is responsible for most of the negative effects we feel. Hangovers, also caused by a buildup of acetaldehyde, may manifest in similar ways. So, how can we tell the difference between alcohol intolerance and alcohol hangovers?

Differences Between Signs of Alcohol Intolerance and Hangovers

Typical signs of a hangover include a range of symptoms:

• Dehydration
• Headache and muscle ache
• Fatigue
• Sensitivity to light and sound 
• Dizziness
• Nausea and vomiting

Although symptoms of hangovers can overlap with symptoms of alcohol intolerance, some signs are more indicative of intolerance:

• Gastrointestinal discomfort such as bloating, pain, flatulence, and nausea
• Skin reactions such as flushing, rash, and hives (which can also occur in other allergic reactions)
• Other allergy symptoms such as exacerbated asthma and nasal congestion 

Now that we’ve learned to better identify between alcohol intolerance and hangover symptoms, let’s delve into other signs that our hangover may be more than just a hangover. 

Common Signs Your Hangover May Be Alcohol Intolerance

Besides distinctive physical reactions, certain other signs can help us figure out when our hangover could be due to alcohol intolerance.

1. You Experience Immediate Symptoms. 

A major difference between hangover symptoms and alcohol intolerance is that hangover symptoms typically occur hours after drinking whereas symptoms of alcohol intolerance can occur immediately. 

The side effects of alcohol intoxication can complicate matters, however, due to overlap with some intolerance symptoms. A racing heartbeat, flushing, and feeling warm, for example, can be signs of intoxication or intolerance. How can we tell which is which? 

If we experience other signs of alcohol intolerance such as GI or respiratory discomfort, congestion, skin changes, or symptoms that occur faster or are especially unpleasant, then it’s most likely alcohol intolerance. Effects of alcohol intoxication aren’t usually distinctly uncomfortable until we’re more heavily intoxicated (which at that point can be dangerous). 

2. You (Actually) Didn’t Drink Much.

It’s easy to underestimate the amount of alcohol we drink. A drink we have at the bar can easily be 2 or 3 standard drinks. However, if we’ve followed moderation guidelines to a T and still experience a worse-than-normal hangover, this may be a telltale sign of alcohol intolerance.

While hangovers are caused by excessive drinking, alcohol intolerance can elicit effects even with minimal amounts of alcohol. Those of us with alcohol intolerance may notice a disproportionate reaction to small amounts of alcohol. 

3. You’re at Higher Risk for Alcohol Intolerance.

Several factors can put us at higher risk for alcohol intolerance.

• Family history and ethnicity. Alcohol intolerance is genetic and heritable. Those of us with a family history of alcohol intolerance are at greater risk for the condition. Individuals of Asian descent are more likely than those of other ethnicities to have this genetic mutation. Research shows that 30%-50% of people of East Asian descent have an intolerance to alcohol. 
• Existing health conditions. Certain health conditions — asthma and other respiratory conditions, histamine intolerance, autoimmune disorders, and gastrointestinal diseases — often co-occur with alcohol intolerance. Additionally, newer studies have concluded that long Covid may also be linked to alcohol intolerance.
• Lifestyle and environmental factors. It’s also important to consider external factors such as diet, alcohol consumption patterns, and other medications and supplements we may be taking. A number of factors can influence severity of hangovers, including drinking on an empty stomach, the amount of alcohol we drink, and the type of alcohol we drink. If we experience a horrific hangover but didn’t eat before drinking, didn’t stay hydrated, or had a couple of glasses of wine (high in congeners), then it’s probably just a bad hangover.

These additional signs may help us recognize alcohol intolerance from general hangovers, but what about alcohol allergy?

Alcohol Intolerance vs. Alcohol Allergy

Alcohol intolerance and allergy are often used interchangeably, but they’re distinctly different. Intolerance is a genetic, metabolic disorder of our digestive system. In short, it’s a change in our genes that impacts how our body breaks down alcohol. 

And alcohol allergy? An allergy is an immune system response to a substance that our body identifies as an intruder — in this case, alcohol, or any of the ingredients it’s made of. As a result, our body produces antibodies to fight it, causing allergy symptoms. An alcohol allergy is more rare than intolerance, and its symptoms are often more serious. Let’s learn how to identify the signs of an alcohol allergy.

Symptoms of Being Allergic to Alcohol

Alcohol allergy symptoms can range from mild to severe. Here are some signs to look out for:

• Rashes
• Itchiness
• Swelling
• Severe stomach cramps
• Trouble breathing
• Anaphylaxis (severe allergic reaction)

Symptoms of anaphylaxis include rapid heart rate, difficulty breathing, nausea or vomiting, low blood pressure, hives, mental confusion, and more. If experiencing any of these or other serious symptoms, call 9-1-1 for emergency medical assistance. 

As we can see, alcohol allergy, alcohol intolerance, and alcohol hangovers are all different. However, alcohol intolerance can impact hangovers. Let’s see how they’re connected. 

The Relationship Between Alcohol Intolerance and Hangovers

Alcohol intolerance can lead to more severe hangovers. Remember how we discussed how hangovers are caused by a buildup of acetaldehyde? Well, since alcohol intolerance impairs our ability to break down acetaldehyde, the pesky toxin extends its stay — leading to a worse hangover.

Aside from having similar symptoms, alcohol intolerance and hangovers share indicators that alcohol is harming our health. Let’s explore some strategies we can add to our toolkit to help us better navigate hangovers and alcohol intolerance.

Managing Alcohol Intolerance and Hangovers

Practicing mindful consumption helps us limit alcohol’s negative effects, reducing the risk of intolerance and hangovers.

• Track signs and symptoms. Having a better understanding of what symptoms we experience and when they appear helps us better differentiate between alcohol intolerance and general hangover symptoms. 
• Quit or cut back on alcohol. Whether it’s alcohol intolerance or general hangover symptoms, quitting or cutting back on alcohol helps us avoid their symptoms.
• Consult with a physician. We may have individual factors that put us at higher risk of alcohol intolerance or hangovers. Consulting with our physician can help us identify these risk factors and develop strategies to ensure we’re prioritizing our health and well-being. 
• Find alternatives to alcohol. It should go without saying, but the underlying factor in alcohol intolerance and hangovers is alcohol. Choosing alcohol-free alternatives eliminates the adverse effects of alcohol and those dreaded hangovers!
• Reach out for support. Developing a healthier relationship with alcohol isn’t always a walk in the park. Luckily, we’re not alone. If we’re concerned about our drinking habits, we can explore a multitude of support options, including opening up to family and friends, joining a community like Reframe, and seeking professional treatment programs.

While distinguishing between alcohol intolerance and hangovers is important, quitting or cutting back on alcohol through these mindful drinking strategies helps us address both. 

The Bottom Line

Alcohol intolerance and hangover symptoms are unpleasant, to say the least. While they manifest similarly, the symptoms of alcohol intolerance have much quicker onset. That, and more common signs of intolerance such as skin reactions and GI discomfort, help us better differentiate between alcohol intolerance and hangovers. By recognizing the differences, we can develop more effective strategies to limit negative effects. With mindful drinking strategies, we can minimize the risk of both. So here’s to a hangover-free morning after!