What is BAC and why are we talking in code? BAC stands for Blood Alcohol Content and it’s not a code. It is something every person needs to know about the effects of alcohol because your blood alcohol content is literally a matter of life or death. BAC is a way to measure a person’s state of intoxication (how drunk he/she is) without having to know which type of drink was consumed or when.

BAC is basically a measurement of the amount of alcohol in your bloodstream. It can be determined by blowing into a special machine (that policemen have, for example) or it can be determined by drawing blood and measuring that sample. When you drink alcohol, it is absorbed into your body and actually enters your bloodstream. Therefore, a blood alcohol content of .2 means that you .2% of your bloodstream is alcohol. Yikes, yes, while your cells need blood to function, they are actually getting some alcohol instead. This is why alcohol poisoning can occur (when your BAC gets high enough, your organs can stop functioning because your cells need the content of blood, but the are getting blood that is poisoned with alcohol).

At what BAC is someone in trouble and at what point are they not okay? 

.02 would represent a low BAC but one where you might begin to feel some effects (relaxation, a little loss of coordination and balance, etc.). 

.06 is when judgement is definitely impaired and at .08 in most states one is considered legally intoxicated and not capable of driving: by .10 a person is legally intoxicated in all states, with significant impairment to his or her functioning: speech, memory, attention and coordination are all impaired. 

At .12 vomiting is likely to occur.  At .20 a person is likely to blackout. 

At .3 a person will likely lose consciousness. 

.45 is considered a lethal level for all individuals. Most people die as breathing stops and vital life functions are not possible.

(Source: http://awareawakealive.org/educate/blood-alcohol-content)

Yes, a person can die from drinking too much alcohol, although remember many people die from alcohol related accidents as well. They might not have had a BAC of  .45 but they had a high enough BAC to impair their abilities, causing a fatal accident that would not have happened if they had not been drinking.

Now, you might be asking, how many drinks cause a BAC of .02 or .08 or .45? That’s a question that is very hard to answer. How much alcohol is in the blood stream depends on many factors: gender (females don’t metabolize alcohol in the same way as males), weight, how much food is in the body, how many drinks, the type of drinks and how quickly they were consumed, are all some of the factors that will affect a person’s BAC. And, as you read in a previous sub-post, tolerance is a factor as well.

But a person always knows he has a BAC of .00 when he doesn’t drink. And that’s a great number to have so that he won’t be at risk for a DUI.