Alcohol is actually a vasodilator. That is why people get flushed when intoxicated. This is why when intoxicated losing body temperature is dangerous...and if extreme, death can occur in cold weather and exposure.

Alcohol is also an anesthetic. In the past when medicine was quite primative, it was given to dull the pain of amputations and surgeries before ether and other anesthetics were discovered.

Alcohol also releases dopamine which is a "feel good" neurotransmitter.

Here is an interesting article about the other complex actions of alcohol that we know about today:
http://www.forbes.com/sites/daviddis...to-your-brain/

The hangover is mostly the result of aldehydes that build up from the metabolism of alcohol and these often are responsible for the sick feeling after alcohol use. The vitamin thiamine is involved in alcohol metabolism and if low, people get sicker drinking less than average amounts of alcohol. This process is also genetically driven, and some people inherit this reaction.

Wine in particular contains poly phenols which also dilate blood vessels. This is why wine is considered a trigger for some migraines.