Are you having some alcohol-related problems? Or just concerned that you may be drinking to much at home, consider how much your blood alcohol concentration (BAC) affects you. If you’re not feeling these effects at these levels, that suggests you’ve developed some tolerance (aka “being able to hold your liquor”). Tolerance though puts you at risk for alcohol related problems.

This is one of a series of blog posts on moderate drinking. The others are available here:

These effects described below are reprinted with permission from Dr. William R. Miller’s publication, Alcohol and its effects on behavior.

.02-.06Light and moderate drinkers begin to feel mildly relaxed and maybe a little light headed. Your inhibitions are slightly loosened, and whatever mood you were in before you started drinking may be mildly intensified. Your behavior may become exaggerated, making you talk louder or faster or act bolder than usual. You may also feel a mild sense of euphoria.
.06Judgment, perception, and information processing are becoming impaired. People are less able to make good judgments, and are more likely to misperceive situations and to take unwise risks. Driving abilities are definitely impaired, because driving requires constant and complex judgment, perception, and information processing. A serious problem is that the drinker usually cannot detect this impairment. You cannot judge when your judgment is impaired or perceive when your perception is impaired
.08Legally Intoxicated in all states in the U.S.. You believe you are functioning better than you actually are. At this level, you may start to slur your speech. Your sense of balance is probably off, and your motor skills are starting to become impaired. Your ability to see and hear clearly is diminished. Your judgment is being affected, so it’s difficult for you to decide whether or not to continue drinking. Your ability to evaluate sexual situations is impaired. Students may jokingly refer to this state of mind as beer goggles, but this BAL can have serious repercussions. People are more likely to take risks they would not take when sober, and are unable to judge accurately their ability to drive.
.10-.12At this level, you feel euphoric, but you lack coordination and balance. Your motor skills are markedly impaired, as are your judgment and memory. You probably don’t remember how many drinks you’ve had. Your emotions are exaggerated, and some people become loud, aggressive, or belligerent. If you’re a guy, you may have trouble getting an erection when your BAC is this high.
.14-.17Your euphoric feelings may give way to unpleasant feelings. You have difficulty talking, walking, or even standing. Your judgment and perception are severely impaired. You may become more aggressive, and there is an increased risk of accidentally injuring yourself or others. This is the point when you may experience a blackout. Vomiting may occur in normal drinkers. Balance and coordination are normally impaired. Heavy drinkers may learn to appear sober at this level, but are in fact intoxicated.
.20You feel confused, dazed, or otherwise disoriented. You need help to stand up or walk. If you hurt yourself at this point, you probably won’t realize it because you won’t feel pain. If you are aware you’ve injured yourself, chances are you won’t do anything about it. At this point you may experience nausea and/or start vomiting (keep in mind that for some people, a lower blood alcohol level than .20% may cause vomiting). Your gag reflex is impaired, so you could choke if you do throw up. Since blackouts are likely at this level, you may not remember any of this. .
.20-.25All mental, physical, and sensory functions are severely impaired. You’re emotionally numb. There’s an increased risk of asphyxiation from choking on vomit and of seriously injuring yourself by falling or other accidents.
.30You’re in a stupor. You have little comprehension of where you are. You may suddenly pass out at this point and be difficult to awaken. (But don’t kid yourself: Passing out can also occur at lower BACs. But, at lower blood alcohol levels, you may decide you’ve had enough to drink and go “pass out.” With an alarming BAC like .30%, your body will be deciding to pass out for you.)
.30-.35This blood alcohol level also happens to be the level of surgical anesthesia. You may stop breathing at this point.
.400You are probably in a coma. The nerve centers controlling your heartbeat and respiration are slowing down.