6 stages of Alcohol Intoxication

Below are the biphasic stages of the effects of alcohol intoxication based on blood alcohol concentration (BAC) variable by individual, body weight, and sex:

1. Euphoria (0.03 to 0.12% blood alcohol concentration)
   • improvement in mood and possible euphoria
   • may become more self-confident or daring
   • may become more friendly or talkative, and/or social
   • attention span shortens
   • may look flushed
   • judgment is not as good - may express the first thought or action that comes to mind rather than an appropriate comment for the given situation
   • may have trouble with fine movements, such as writing or signing their name
2. Lethargy (0.09 to 0.25% blood alcohol concentration)
   • may become sleepy
   • trouble understanding or remembering things, even recent events
   • Does not react to situations as quickly
   • body movements are uncoordinated; they begin to lose their balance easily, stumbling; walking is not stable
   • vision becomes blurry
   • may have trouble sensing things (hearing, tasting, feeling, etc.)
3. Confusion (0.18 to 0.30% blood alcohol concentration)
   • profound confusion—uncertain where they are or what they are doing
   • dizziness and staggering occur
   • heightened emotional state—aggressive, withdrawn, or overly affectionate
   • vision, speech, and awareness are impaired
   • poor coordination and pain response
   • nausea and vomiting sometimes occurs.
4. Stupor (0.25 to 0.40% blood alcohol concentration)
   • movement severely impaired
   • lapses in and out of consciousness
   • can slip into a coma
   • will become completely unaware of surroundings, time passage, and actions
   • risk of death is very high due to alcohol poisoning and/or pulmonary aspiration of vomit while unconscious
   • loss of bodily functions can begin, including bladder control, breathing, heart rate.
5. Coma (0.35 to 0.50% blood alcohol concentration)
   • unconsciousness sets in
   • reflexes are depressed (i.e., pupils do not respond appropriately to changes in light)
   • breathing is slower and more shallow
   • heart rate drops
   • death usually occurs at levels in this range
6. Death (more than 0.50% blood alcohol concentration)
   • Can cause central nervous system to fail, resulting in death.

How Alcohol Effects Us: The Biphasic Curve

Most people think that if a few drinks make them feel good then a lot of drinks will make them feel even better. But that’s not true. Although a few drinks will make them feel better, more will make them feel worse. It’s called the biphasic (or two part) effect. Here’s what happens.