Normally, the liver produces two enzymes, ethanol dehydrogenase and acetaldehyde dehydrogenase, after drinking alcohol.
The alcohol ingested by the body is broken down into acetaldehyde by the action of ethanol dehydrogenase, which is then broken down into carbon dioxide and water by the action of acetaldehyde dehydrogenase, thus providing energy for the body. A deficiency of acetaldehyde dehydrogenase can lead to the accumulation of acetaldehyde in the body, causing vasodilation of the facial skin and resulting in facial redness.
If it is accompanied by symptoms such as breathing difficulties, nausea, vomiting, sweating, chest pain, low blood pressure, fainting, blurred vision and confusion, it may be related to acetaldehyde syndrome and prompt medical attention should be sought.