Intolerance Lab

Visit our page for more information on Easy Affordable at Home Intolerance Testing

Alcohol intolerance

Alcohol can help you unwind after a long day at work, complement a yummy meal, and even reduce social anxiety and boost your mood. However, drinking alcohol can quickly lead to intoxication and unpleasant affects – especially if you’re intolerant to alcohol. If you’ve noticed that you often feel a rush of heat and redness after drinking wine, or your nose gets a bit stuffy, then you may have alcohol intolerance. Today we’re going to explore what alcohol intolerance is, how it can make you feel, what puts you at risk of alcohol intolerance, and how you can tell if you have alcohol intolerance or an alcohol allergy. Let’s begin.

What is alcohol intolerance?

Alcohol intolerance is an unpleasant or uncomfortable reaction that happens after you drink alcohol. It is considered an ‘inherited metabolic disorder’ because it is often caused by a gene mutation from your parents that affects the way that you break down alcohol.  If you don’t break down alcohol properly, it builds up in your body and causes adverse symptoms. Even drinking a small amount of alcohol can cause these symptoms if you have alcohol intolerance.

Symptoms of alcohol intolerance

The two most common symptoms of alcohol intolerance are a blocked or runny nose, and facial flushing. The flushing happens when your face, neck, or chest become red and warm after drinking alcohol. 

Other symptoms of alcohol intolerance include:

  • a headache (like you’re hung over)
  • a fast heartbeat, or palpitations
  • low blood pressure
  • fatigue or drowsiness
  • red and itchy skin, or hives
  • nausea 
  • vomiting
  • diarrhoea
  • worsening of lung issues (like asthma)

What causes alcohol intolerance?

Alcohol intolerance happens when your body has a problem with breaking down alcohol properly. This can happen because of:
  • an issue with a liver enzyme Alcohol is normally broken down by the liver enzyme ALDH2. However, in some people this enzyme isn’t working properly, or they have a gene defect that stops the ALDH2 enzyme from processing alcohol the way it should. This is common in Asians.
  • poor liver health Because the liver is responsible for breaking down alcohol, if you have issues with your liver then the alcohol doesn’t get metabolised and it stays in your body for longer than it used to.
  • aging Changes to your body as you age affects the way you can handle alcohol. Firstly, your body composition (the amount of muscle, water and fat in your body) changes and you get a higher level of alcohol in your blood when you drink. Your liver health also declines with age, which impairs your ability to break down alcohol (as we saw above).
  • mixing medications and alcohol Certain medications increase the effects of alcohol and can give you symptoms of alcohol intolerance. It’s important to speak with your doctor or pharmacist to make sure you can have alcohol while taking your medications. .

You may also have an intolerance to alcohol if your body is reacting to other ingredients in the alcohol, such as:

  • the grapes or grains used to make the alcohol
  • chemicals used while growing the plants
  • sulphites or other preservatives used to prolong the shelf-life of the alcohol
  • histamine (a natural substance produced while making the alcohol)

Risk factors for alcohol intolerance

Your risk of having alcohol intolerance is increased if:


  • you’re of east Asian decent (in particular, Chinese, Korean and Japanese people have been found to have problems with the ALDH2 enzyme that breaks down alcohol)
  • you have hay fever or asthma
  • you have an allergy to grains (e.g., corn, rye) or other foods used to make alcohol
  • you have Hodgkin’s lymphoma (which can cause severe pain after drinking alcohol) 
  • you have Gilbert’s syndrome (a liver condition)
  • you are female and have a tumour on your uterus, breast, or ovaries
  • you have menopause worsening the symptoms of alcohol intolerance (like flushing and night sweats)

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

Sometimes an alcohol intolerance is confused for an alcohol allergy. However, these are two very different reactions to alcohol. 


We’ve learnt that an alcohol intolerance is caused by an issue with breaking down the alcohol. Alcohol is by its very nature a poison, so it needs to be metabolised by the ALDH2 enzyme in the liver in order to make it inactive and no longer toxic. If the ALDH2 enzyme is not working properly, or you don’t have enough of it, then the toxic alcohol builds up in your blood and tissues and causes the symptoms of alcohol intolerance. The symptoms can be mild or moderate, and come on immediately after drinking. 


An allergy to alcohol is caused by an immune reaction to one of the ingredients in alcohol. You may be allergic to the grains used to make the alcohol, or to a chemical or preservative in the alcohol. The symptoms of alcohol allergy are often more uncomfortable and severe than an alcohol intolerance. Although rare, an alcohol allergy can even be life-threatening if left untreated. 


The symptoms of alcohol allergy include:


  • skin rashes, hives, or eczema
  • itchy eyes, nose or mouth
  • swelling of your face, neck or other body parts
  • a blocked or runny nose
  • wheezing or difficulty breathing
  • a stomach-ache
  • nausea
  • vomiting
  • diarrhoea
  • dizziness
  • loss of consciousness


If you have symptoms of alcohol allergy, seek immediate medical attention. 

Testing for alcohol intolerance

Having an intolerance to alcohol may be less severe than an alcohol allergy. However, the symptoms can be incredibly unpleasant and challenging to live with. If you’re unsure whether or not you have alcohol intolerance, then the only way to find out is to test for it. You can do this by ordering our intolerance test online HERE. The test looks at over 500 food and other intolerances and can provide you with results within 3 days of us receiving your sample. This is a quick and non-invasive way of finding out if you are intolerant to alcohol.


To summarise, today we’ve looked at alcohol intolerance and how it may be affecting you. We explored a range of things that can lead to alcohol intolerance, as well as various factors that can increase your risk of developing an intolerance to alcohol. We then compared alcohol intolerance to having an alcohol allergy and learnt that the causes and symptoms of these two reactions are very different. Lastly, we looked at how you can test for alcohol intolerance using our easy test, which you can order online HERE.

Leave a Reply

Your email address will not be published. Required fields are marked *