Alcohol Flush Reaction is a physical response that occurs in some individuals after consuming alcohol. It is characterized by facial redness, warmth, and sometimes itching. This reaction is most common among people of East Asian descent due to a genetic variation that affects the metabolism of alcohol. The flush is caused by the accumulation of acetaldehyde, a toxic byproduct of alcohol metabolism. Normally, the body breaks down acetaldehyde into a less harmful substance, but in those with the flush reaction, this process is impaired. This can lead to discomfort and may discourage some individuals from drinking alcohol.