Being drunk means your body has absorbed enough alcohol to noticeably impair your brain function. At its core, drunkenness is a form of central nervous system depression: alcohol slows down the signals your brain sends and receives, which changes how you think, move, feel, and react. The effects range from mild relaxation after one drink to life-threatening shutdown of basic body functions at very high levels.
What Alcohol Does to Your Brain
When you drink, alcohol passes through your stomach lining and small intestine into your bloodstream, then reaches your brain within minutes. Once there, it amplifies your brain’s main “slow down” chemical while suppressing its main “speed up” chemical. The result is a net decrease in brain activity. Your brain also releases more of the chemicals linked to pleasure and reward, which is why the early stages of drinking feel good.
This slowdown doesn’t hit every part of your brain equally. The areas responsible for judgment, impulse control, and decision-making are affected first, even at low levels of alcohol. That’s why people often say or do things while drunk that they wouldn’t sober. As you drink more, the areas controlling coordination, balance, speech, and eventually automatic functions like breathing and heart rate become impaired too.
How Drunkenness Feels at Different Levels
Blood alcohol concentration (BAC) measures how much alcohol is in your bloodstream as a percentage. Even small increases can change how you feel and function.
At 0.01 to 0.05% BAC (roughly one drink), you may feel relaxed, slightly less alert, and notice a mild loosening of your usual judgment. Most people wouldn’t call this “drunk,” but impairment has already started.
At 0.06 to 0.15% BAC (two to four drinks, depending on your body), the classic signs of being drunk appear: slurred speech, reduced coordination, impaired balance, and clouded judgment. Memory starts becoming unreliable. This is the range most people picture when they think of someone who’s had too much.
At 0.16 to 0.30% BAC, the effects become more serious. Walking and speaking get genuinely difficult. You may feel drowsy, confused, or nauseated. Blackouts, which are gaps in memory where your brain stops recording events even though you’re awake, become likely. Vomiting and loss of consciousness can happen.
Above 0.31% BAC, the situation turns dangerous. You may lose consciousness, have trouble breathing, or slip into a coma. This level can be fatal.
Why Some People Get Drunk Faster
Your liver processes alcohol at a remarkably steady rate: about one standard drink per hour. It can’t be rushed. Drinking faster than your liver can work means alcohol accumulates in your blood and your BAC climbs.
A “standard drink” in the United States contains 0.6 ounces (14 grams) of pure alcohol. That translates to 12 ounces of regular beer (5% alcohol), 5 ounces of wine (12% alcohol), or 1.5 ounces of liquor (40% alcohol). Many cocktails and craft beers contain significantly more than one standard drink per glass, which catches people off guard.
Several factors determine how quickly a given amount of alcohol raises your BAC. Body size matters: a smaller person has less blood volume, so the same drink produces a higher concentration. People with more body fat and less water in their tissues tend to reach higher BAC levels from the same amount of alcohol. Whether you’ve eaten also makes a big difference. Food in your stomach slows absorption, meaning alcohol enters your bloodstream more gradually. Drinking on an empty stomach lets alcohol pass into your small intestine quickly, producing a faster, sharper spike in BAC.
Being Drunk vs. Alcohol Poisoning
There’s a critical line between being drunk and experiencing an alcohol overdose, and it’s not always obvious from the outside. Being drunk involves impaired coordination, poor judgment, slurred speech, and emotional changes. Alcohol poisoning occurs when there’s so much alcohol in your bloodstream that the brain areas controlling breathing, heart rate, and body temperature begin shutting down.
The warning signs of alcohol poisoning include: mental confusion beyond normal drunkenness, difficulty staying conscious, vomiting (especially while unconscious), seizures, slow or irregular breathing, a very slow heart rate, clammy skin, extremely low body temperature, and a loss of the gag reflex, which means someone could choke on their own vomit. Someone doesn’t need to show every symptom for the situation to be an emergency.
The Legal Meaning of “Drunk”
Legally, “drunk” usually refers to a specific BAC threshold rather than how you feel. In the United States, the legal limit for driving is 0.08% BAC in all 50 states, though impairment begins well below that number. In most of Europe, the limit is stricter at 0.05%, and several countries, including the Czech Republic, Hungary, Romania, and Slovakia, enforce a zero-tolerance policy. The UK (excluding Scotland) sets its limit at 0.08%, the highest in Europe.
For new and commercial drivers, limits are often lower. Germany, Italy, and Croatia set a 0.0% limit for novice drivers, while France and the Netherlands allow no more than 0.02%. These stricter rules reflect the fact that even very low BAC levels measurably reduce reaction time and coordination.
How Long It Takes to Sober Up
Your BAC drops by roughly 0.015 per hour. That means if you stop drinking at a BAC of 0.08%, it takes about five and a half hours to reach zero. At 0.15%, you’re looking at around ten hours. Nothing speeds this up. Coffee, cold showers, food, and exercise don’t change the rate your liver processes alcohol. They might make you feel more alert, but your coordination and judgment remain impaired until your BAC actually drops.
This is why people can still be legally drunk the morning after a night of heavy drinking. If your BAC peaked at 0.20% when you stopped at midnight, you wouldn’t reach 0.08% until roughly 8 a.m., and you wouldn’t be completely sober until after noon.