<unk>  is best known as a condition that is experienced by people of East Asian descent; due to this, the condition is often given names such as "Asian<unk> " or "Asian glow". Genotype frequency distribution of ALDH2 (rs671). Around 30–50% of East Asians carry the rs671 (ALDH2*2) allele on chromosome 12, which results in a less functional acetaldehyde dehydrogenase enzyme, responsible for the breakdown of acetaldehyde, and accounts for most incidents of<unk>  worldwide. According to the analysis by HapMap project, 30% to 50% of people of Chinese, Japanese, and Korean ancestry have at least one ALDH2*2 allele, while it is rare among Europeans and Sub-Saharan Africans. The rs671 allele is native to East Asia and most common in southeastern China. Analysis correlates the rise and spread of rice cultivation in South China with the spread of the allele. The reasons for this positive selection are not known, but it has been hypothesized that elevated concentrations of acetaldehyde may have conferred protection against certain parasitic infections, such as Entamoeba histolytica. Additionally, in around 80% of East Asians, the rapid accumulation of acetaldehyde is worsened by another gene variant; in this case the allele ADH1B*2, which results in the alcohol dehydrogenase enzyme converting alcohol to toxic acetaldehyde more quickly than other gene variants common outside of East Asia.
Alcohol flush reaction
Cannabinoid hyperemesis syndrome
Alcohol withdrawal syndrome
Post-acute-withdrawal syndrome
Nicotine withdrawal
Drug withdrawal
Poison ivy 
Opioid withdrawal