Waking up after a night of drinks feeling groggy, nauseous and dealing with that pounding headache but while most of us chalk it up to a classic hangover, what if your body is actually trying to tell you something more serious? According to experts, that awful feeling after drinking may not always be due to overindulgence—it could be alcohol intolerance or even an allergy.

More than just a hangover
“A hangover happens when you drink more alcohol than your body can handle,” said Dr Raj Dasgupta, an internal medicine specialist with Huntington Health in Los Angeles. “It’s a combination of dehydration, electrolyte imbalance, inflammation, and your liver working overtime to process alcohol.”
While unpleasant, a hangover is temporary and can often be minimised by pacing yourself and staying hydrated but if you experience certain symptoms immediately after consuming alcohol, something else might be at play.
Alcohol intolerance: When your body can’t handle booze
If you find yourself turning red, feeling nauseous, or experiencing a rapid heartbeat soon after just a sip or two, you may have alcohol intolerance. Dr Dasgupta explained, “Alcohol intolerance is a reaction that happens quickly, often within minutes of consuming even a small amount of alcohol. This isn’t about drinking too much—it’s your body signaling that it can’t handle alcohol well at all.”

People with alcohol intolerance have an enzyme deficiency, preventing them from properly breaking down alcohol. Common symptoms include:
- Flushing, especially in the face
- A stuffy nose
- Nausea
- A racing heartbeat
This condition is more common among individuals of East Asian descent due to a genetic mutation that affects alcohol metabolism. While not dangerous, it can make drinking an uncomfortable experience.
Could it be an alcohol allergy?
Although rare, some people may actually have an alcohol allergy. Unlike alcohol intolerance, which is caused by an enzyme deficiency, an alcohol allergy is an immune system response to specific ingredients found in alcoholic beverages.

“An alcohol allergy is much rarer but also more serious,” revealed Dr Dasgupta. “It’s an immune response to something in the drink, such as barley, wheat, yeast, or sulfites.”
Symptoms of an alcohol allergy typically appear almost immediately after consuming alcohol and can include:
- Hives or skin rash
- Swelling (especially in the face, lips, or throat)
- Difficulty breathing
- Stomach pain or nausea
- Anaphylaxis (a life-threatening reaction requiring immediate medical attention)
If you experience swelling or breathing difficulties after drinking, Dr Dasgupta asserted you seek medical help immediately.
Knowing the difference
So, how can you tell if it’s just a hangover or something more serious? The timing of your symptoms is key.
- A hangover develops hours after drinking and typically fades with rest, hydration, and time.
- Alcohol intolerance triggers symptoms almost immediately, including flushing and nausea.
- An alcohol allergy can cause severe reactions, such as swelling or breathing difficulties, and requires urgent medical attention.
Listen to your body
If you often feel sick after drinking—even just a little—it may be worth discussing your symptoms with a doctor. “When in doubt, talk to your doctor. They can help you figure it out and stay safe,” advised Dr Dasgupta.
While a hangover might be an inconvenience, a more serious reaction could indicate an underlying condition that needs attention. So the next time you are feeling unwell after a drink, pay close attention—your body might be trying to tell you something important.
Disclaimer: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.