Alcohol

What it feels like

Drink by drink, from the first to too many.

As you keep drinking

• The first drinks, Warm and loose: Reward circuits switch on and the brain's response to threat dulls — things feel good and risks feel smaller.
• Before you feel it, The eyes go first: Even at a dose too small to feel drunk, the eyes track moving things less smoothly.
• Drunk, Unsteady: Coordination and balance go as alcohol disrupts the cerebellum.
• Very drunk, Seeing double, losing the night: The two eyes' images stop fusing — double vision. New memories stop being stored, which is a blackout.
• Too much, Poisoning: Confusion, vomiting, slow or irregular breathing, can't be woken.

What it can feel like

• Good: Rewarding — and more so the more drunk people feel.
• Brave: Fear fades; frightening faces register less.
• Clumsy: Unsteady on your feet.
• Blurry: Eyes slow to follow things, and later, doubling.
• Gaps: Bits of the night that were never recorded.

How fast you get there depends on more than the number of drinks. Young people reach binge-level blood alcohol on fewer drinks — about three for girls and three to five for boys, against four or five for adults.

What's happening in the brain

Each part of being drunk, traced to where it happens. The model lights each one as you read.

Reward up

Alcohol switches on the striatum's reward circuits — more strongly the more intoxicated people feel. That's the warmth of the first drinks, and part of why the next one is easy.

Fear down

It dulls the brain's response to fearful faces in visual and limbic areas. Danger registers less — which is how people end up doing things they never would sober.

Balance

Alcohol disrupts signalling in the cerebellum, partly by increasing GABA release there, which is behind the stagger and the clumsiness.

Blackouts

Alcohol mainly blocks the forming of new memories and leaves older ones alone. At high amounts it can cause blackouts — partly by disrupting the hippocampus. You were there; your brain just didn't record it.

Breathing

The brainstem keeps you breathing and your heart beating. At very high levels, alcohol's slowing of the nervous system deepens into coma — and the signs of poisoning, like slow or irregular breathing, are the brainstem's work failing.

Risks and staying safe

The risks plainly, and what to do if someone's had far too much.

The real risks

• Poisoning: Too much can bring coma and death.
• Mixing: With opioids, sleeping pills, benzodiazepines or antihistamines it's dangerous.
• Cancer: Alcohol causes at least seven cancers, and the WHO says no amount is safe for health.
• Dependence: Signs include drinking more than intended, failing to cut down and needing more for the same effect; it's treatable, and many people recover.
• Starting young: Starting before 15 raises the later risk of alcohol use disorder.

Signs of alcohol poisoning

• Confusion, or can't be woken.
• Vomiting, or seizures.
• Slow breathing, or gaps of 10 seconds or more between breaths.
• Clammy, pale or bluish skin; very low body temperature.

What to do

1. Call emergency services: Straight away — don't wait for every sign.
2. Never leave them: They can fall or choke.
3. On their side: If they're unconscious, roll them onto their side, ear to the ground.
4. Forget the myths: Coffee, cold showers and walking don't sober anyone up.

Check what you know

Five questions about what alcohol is doing.

• After a few drinks, jumping off the harbour wall into the sea suddenly seems like a great idea. What's alcohol doing? Dulling the brain's response to threat while switching reward circuits on. Alcohol dulled responses to fearful faces and activated the striatum's reward circuits.
• You remember arriving at the party and getting home, but not the two hours in between — though friends say you were chatting the whole time. What happened? A blackout: alcohol stopped your hippocampus from saving new memories. Alcohol mainly blocks the forming of new memories, and at high amounts causes blackouts, partly by disrupting the hippocampus.
• Someone has had one drink, feels completely sober, and is about to drive. Is anything affected yet? Yes — eye tracking is impaired even at a dose too small to feel. Alcohol impaired smooth tracking eye movements in proportion to dose — even at a non-intoxicating dose.
• Late in the night, everything has a double. Why? Alcohol slows the eyes from fusing their two images into one. Double vision is a frequent symptom of severe intoxication; alcohol slows fusing and narrows the distances it works over.
• A friend stopped drinking an hour ago and has just passed out. Someone says she's past the worst. Is she? Not necessarily — blood alcohol can keep rising after the last drink, even while she's unconscious. Alcohol in the stomach keeps entering the blood; it's dangerous to assume she'll sleep it off. Stay with her, on her side, and get help if she can't be woken.