Is It a Hangover or Alcohol Intolerance?

Have you ever woken up feeling terrible after just one drink? Maybe you misjudged how much wine was in that oversized glass at a party. Or perhaps you forgot how strongly certain compounds—called congeners—in red wine affect you. It’s also possible you’re not actually hungover, but experiencing alcohol intolerance instead.

Because hangovers and alcohol intolerance share many symptoms, it can be tricky to tell them apart. Let’s explore the differences.

What Is Alcohol Intolerance?

Alcohol intolerance is a condition where your body struggles to break down and process toxins in alcohol. It’s caused by a genetic mutation affecting enzymes that metabolize alcohol. This is different from having a low alcohol tolerance, where you still have normal enzymes but feel the effects of alcohol more quickly.

Normally, your body processes alcohol like this:

• An enzyme called alcohol dehydrogenase (ADH) breaks ethanol down into acetaldehyde—a toxic compound.
• Aldehyde dehydrogenase (ALDH) then converts acetaldehyde into acetate.
• Acetate is broken down into water and carbon dioxide and eliminated.

With alcohol intolerance, ADH and ALDH enzymes are less active, leading to a buildup of acetaldehyde. This causes many of the unpleasant symptoms you feel. Since hangovers are also linked to acetaldehyde buildup, the two can feel similar. So how do you tell them apart?

Hangover vs. Alcohol Intolerance Symptoms

Common hangover symptoms include:

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

While some symptoms overlap, alcohol intolerance often involves:

• Digestive issues like bloating, pain, gas, or nausea
• Skin reactions such as flushing, rash, or hives
• Worsened asthma or nasal congestion

Signs Your Hangover Might Be Alcohol Intolerance

Here are a few clues that your symptoms could point to intolerance:

• Symptoms appear quickly: Hangover symptoms usually show up hours after drinking, but intolerance symptoms can start almost immediately.
• You didn’t drink much: If you followed moderation guidelines carefully but still feel awful, it could be intolerance. Hangovers usually follow heavy drinking, but intolerance can occur after just a small amount.
• You’re at higher risk: Factors like family history, ethnicity (especially East Asian descent), asthma, histamine intolerance, or autoimmune conditions can increase your risk of alcohol intolerance.

Alcohol Intolerance vs. Alcohol Allergy

It’s important not to confuse intolerance with an allergy. Alcohol intolerance is a metabolic issue caused by genetics. An alcohol allergy, however, is an immune response where your body treats alcohol or its ingredients as a threat. Allergy symptoms can be more severe and include:

• Rashes or itchiness
• Swelling
• Severe stomach cramps
• Difficulty breathing
• Anaphylaxis (a life-threatening reaction)

If you experience serious symptoms like trouble breathing or confusion, seek emergency medical help immediately.

How Alcohol Intolerance Affects Hangovers

If you have alcohol intolerance, you may experience worse hangovers. Since your body struggles to clear acetaldehyde, this toxin lingers longer, intensifying hangover symptoms.

Managing Symptoms and Reducing Risk

Whether you’re dealing with intolerance or frequent hangovers, these strategies can help:

• Track your symptoms: Note what you feel and when—this can help identify patterns.
• Cut back or quit alcohol: Reducing alcohol intake is the most effective way to avoid symptoms.
• Talk to a doctor: A healthcare provider can help identify risk factors and suggest personalized strategies.
• Choose non-alcoholic options: Opting for alcohol-free drinks eliminates the risk entirely.
• Seek support: If you’re looking to build a healthier relationship with alcohol, consider talking to friends, joining a community like Quitemate, or exploring professional programs.

Final Thoughts

While alcohol intolerance and hangovers can feel similar, intolerance symptoms usually appear faster and may include skin or digestive issues. Recognizing the difference helps you take the right steps to feel better. By drinking mindfully and making informed choices, you can reduce unpleasant symptoms and enjoy more comfortable mornings.