This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Alcohol intolerance is characterized by immediate unpleasant reactions after drinking alcohol. The most common signs and symptoms of alcohol intolerance are stuffy nose and skin flushing. Alcohol intolerance is caused by a genetic condition in which the body is unable to break down alcohol efficiently. It is most common in Asians. These individuals accumulate acetaldehyde, the primary metabolite of ethanol, because of a genetic polymorphism that doesn’t allow aldehyde dehydrogenase (ALDH) to metabolize acetaldehyde to nontoxic acetate. The only way to prevent alcohol intolerance reactions is to avoid alcohol. Alcohol intolerance isn’t an allergy. However, in some cases, what seems to be alcohol intolerance may be a reaction to something in an alcoholic beverage, such as chemicals, grains, or preservatives. Combining alcohol with certain medications also can cause reactions. In rare instances, an unpleasant reaction to alcohol can be a sign of a serious underlying health problem that requires diagnosis and treatment.
For more information, visit GARD.