Redness all over the body after drinking alcohol is a sign of acetaldehyde poisoning. After alcohol enters the body, it is changed into acetaldehyde by the action of ethanol dehydrogenase, which is then metabolized and discharged from the body by the action of acetaldehyde dehydrogenase in the liver. If the human liver lacks acetaldehyde dehydrogenase, it will lead to excessive accumulation of acetaldehyde in the body, resulting in redness of the face or even the whole body, and in serious cases, chest tightness, breathing difficulties, anaphylaxis, etc. If the whole body is red after drinking, you should also be alert to whether the patient has an alcohol allergy and develops allergic dermatitis and rash. Regardless of the cause of redness after drinking alcohol, patients should drink more water and urinate more to help metabolize the ethanol out of the body as soon as possible, and try to reduce alcohol consumption in the future.