Alcohol does terrible things. David Hasselhoff does too.
A recent study in the British medical journal The Lancet (here's a link to a news story summary) shows that alcohol is more lethal and does more overall harm than heroin or cocaine.
According to Chinese medical theory, alcohol is hot, acrid and toxic. In small amounts it can be beneficial as it moves the blood and warms the channels. Alcohol tinctures are a big part of Chinese herbal medicine, although they're not used extensively in the U.S. In large amounts, however, it can create Damp Heat and cause one to "forget oneself".
Alcohol is processed by the liver. In Chinese medical theory, the Liver is the home of the 魂神 Hun Shen, or ethereal spirit (The Liver stores the ethereal soul - gan cang hun 肝藏魂 from Statements of Fact in Traditional Chinese Medicine by Bob Flaws). If the Liver is working properly qi flows easily in the body and you feel at ease.
("Liver qi stagnation" is a common translation, some would say mistranslation, of 肝氣郁 gan qi yu - Bob Flaws and Nigel Wiseman prefer Liver qi depression as the more accurate translation. "Depression" here does not mean the Western medical condition mental depression - rather it indicates a kind of improper or lower-level functioning of the Liver qi. It may or may not be "stagnated" in the sense of a blockage. With that caveat...)
If, however, Liver qi becomes depressed (see previous paragraph), a small amount of alcohol may help to move things along. This is why people drink in social situations - besides the ritual of engaging in a common activity, the substance itself, in this case alcohol, dissolves barriers and loosens tongues. The key is knowing when to stop... excessive alcohol can lead to ugly situations like this and this.
