饮酒后脸红是怎么回事？
酒精（乙醇）通过胃部被身体吸收，而肝脏负责血液循环并通过两个步骤分解酒精：
1. 首先醇脱氢酶（ADH）会将乙醇转化为乙醛。乙醛是一种对身体有害的物质。
2. 接着醛脱氢酶（ALDH）会将乙醛转化为乙酸。乙酸对人体是无害的，并且能在体内被分解为水和二氧化碳。
如果肝脏不能及时将乙醛转化为乙酸，乙醛就会在血管内堆积，从而引起脸部泛红。因此出现酒后脸红反应的人应该及时减缓或停止饮酒。
The meaning of flushing
Alcohol (CH3CH2OH) is absorbed into the blood stream through the stomach. Blood is sent through the liver, where the liver breaks down the alcohol in 2 stages:
1. In the first stage the enzyme alcohol dehydrogenase (ADH) converts alcohol into acetaldehyde. Acetaldehyde is toxic to humans.
2. In the second stage the enzyme aldehyde dehydrogenase (ALDH) converts acetaldehyde into acetic acid. Acetic acid is harmless to humans. Acetic acid is further metabolised and leaves the body as carbon dioxide and water.
If the liver cannot convert acetaldehyde into acetic acid quickly enough, the acetaldehyde accumulates in the bloodstream. The accumulation of acetaldehyde in the blood is the reason for flushing when drinking (turning red in the face or neck). It is recommended to a person who flushes that he or she slow down or stop drinking alcohol.