How Does Alcohol Kill?
Alcohol can cause death directly by acting on those brain areas that control consciousness, respiration and heart rate. As a central nervous system depressant, alcohol can "turn off" these vital brain areas, resulting first in coma and then death.
In many cases, drinking too much alcohol will make you sick and you will stop drinking. Contrary to folk tales, getting sick is not from mixing drinks or drinking on an empty stomach, it is because specialized poison control cells in your brain detect danger -- too much alcohol -- and send a signal to your stomach to vomit. This is the brain's way of dealing with poisoning. Vomiting is an attempt to eliminate any unabsorbed alcohol. The logic is, if you can prevent any alcohol that's still in the stomach from getting into the blood supply, it may save your life. Eating before you drink will slow down the speed of intoxication but it is no guarantee that you won't get sick or die if you consume enough alcohol.
Whereas some people only vomit when they have consumed too much alcohol, other people just fall asleep (with or without vomiting) after they have consumed too much alcohol. In these people, death can follow in one of two ways: you may fall into a deep sleep and vomit while sleeping. What's the result? You choke on your own vomit because you are too intoxicated to wake up and clear out your airway. In other instances, you simply fall asleep and never wake up, because the concentration of alcohol is so high that the areas of your brain controlling life functions are so depressed that they stop functioning and so do you.
How Much Alcohol Is "Lethal"?
The "lethal dose" (LD) of alcohol is clinically defined as the amount that would kill half the population (the LD50). Most authorities place the LD50 at about .40% or about four times the current legal limit in most states. However, there are many cases in which death occurred from alcohol poisoning at much lower, and in some cases, much higher levels. For a 100 lb. man or woman drinking very quickly, it would only require about 8-10 drinks in an hour to reach the lethal level.