Alcohol poisoning – what to look out for and when to get medical help

Alcohol poisoning can be life-threatening. This guide explains the warning signs, what to do, and when to get medical help.

What is alcohol poisoning?
What are the early signs of alcohol poisoning?
What do we mean by alcohol building up to dangerous levels?
This is how alcohol builds up in the body
When to get help
How to help someone with alcohol poisoning
What to expect in hospital
How alcohol affects your brain and behaviour
Mixing alcohol with other drugs
Safer drinking tips
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Further alcohol support and information

What is alcohol poisoning?

Alcohol poisoning is a serious condition that happens when you drink too much alcohol in a short time. Your body can't process it fast enough, so alcohol builds up to dangerous levels and starts to affect vital functions like:

Breathing
Heartbeat
Keeping body temperature steady
The gag reflex (which stops someone from choking)

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What are the early signs of alcohol poisoning?

Confusion or trouble staying awake
Vomiting
Clammy skin
Slow heart rate and breathing

Alcohol poisoning is a medical emergency. It can lead to brain damage or death if you don't get help. If you're with someone who needs help call 999 straight away and stay with them until help arrives.

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What do we mean by alcohol building up to dangerous levels?

You build up alcohol in your body when you drink more than your body can process. The strength of a drink is measured in units of alcohol. Your liver can break down about 1 unit per hour. If you drink too quickly, alcohol builds up in your blood. This can lead to alcohol poisoning — even after you've stopped drinking — because your body is still absorbing alcohol it hasn't processed yet.

Different drinks contain different amounts of alcohol. Here are some common examples:

A single shot of spirits (25ml at 40%) = 1 unit
A small glass of wine (125ml at 12%) = 1.5 units
A pint of strong beer or cider (568ml at 5%) = about 2.8 units

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This is how alcohol builds up in the body

A pint of strong beer or cider (around 5%) contains about 2.8 units. Since your liver processes about 1 unit per hour, it could take nearly 3 hours to break down fully.

Drink two pints (about 5.6 units) and it could take 5 to 6 hours to clear from your system. Three pints (8.4 units) could take over 8 hours.

Alcohol can build up quickly, especially if someone drinks several drinks close together. The body can't keep up — and that's when the risk of alcohol poisoning increases, even after drinking stops.

Everyone processes alcohol at different rates

How long it takes to break down alcohol varies from person to person, the unit time above is an average. It depends on body size, sex (women often feel the effects more quickly due to size and metabolism), age, how fast you drank, whether you've eaten (food slows down how quickly alcohol is absorbed into the bloodstream), and if you've used any other drugs.

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When to get help

This section provides a quick comparison to help determine whether someone requires urgent assistance.

Drunk

The person appears relaxed, talkative or unsteady
They may slur their speech or lose balance

Signs to watch for:

Minor stumbling
Slightly slower reactions

▸ No medical help is usually needed — just food, rest and time.

Dangerously intoxicated

The person is drowsy, confused or behaving unusually
They may vomit, fall, or pass out briefly, then wake up

Signs to watch for:

Difficulty walking in a straight line
Confusion about where they are
Vomiting more than once

▸ They should not be left alone and may need monitoring.

Alcohol poisoning

Even one serious symptom could mean alcohol poisoning. If someone shows any of the signs below, call 999 immediately.

The person may be unconscious, breathing slowly or irregularly
Have pale or blue skin, or experience seizures

Signs to watch for:

Cannot be roused by shouting their name or light shaking
No response to touch, sound, or movement

▸ This is life-threatening — call 999 immediately

✖

Alert
If someone seems "just drunk", they could quickly become dangerously intoxicated or experience alcohol poisoning. These stages can change rapidly — check on them regularly, and if unsure whether it's an emergency, call NHS 111 for advice, call 999, or take the person to hospital.

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How to help someone with alcohol poisoning

Do:

Stay with the person
Sit them up if they are awake (preferably on the floor)
If unconscious, place them in the recovery position (on their side with one ear to the ground)
Check their breathing
If they can swallow, offer small sips of water
Keep them warm with a jacket or blanket

Don't:

Don't give more alcohol
Don't offer coffee or caffeinated drinks
Don't walk them around — they could fall
Don't put them in a cold shower or bath — risk of shock or unconsciousness
Don't try to make them vomit — they could choke

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What to expect in hospital

If someone is taken to A&E for alcohol poisoning, hospital staff will follow a standard process. This may vary slightly between hospitals but generally includes the steps below.

Triage assessment

A nurse or healthcare worker will assess how serious the situation is and prioritise care accordingly.

Medical assessment

A doctor will examine the person, order any necessary tests, and decide on appropriate treatment.

Monitoring and treatment

Vital signs such as breathing, heart rate and temperature will be closely monitored. The person may receive fluids, medication or care for alcohol withdrawal symptoms.

Support and advice

Hospital staff may offer information on alcohol risks, safer drinking, and referrals to support services.

Referral or discharge

Depending on their condition, the person may stay for observation or be sent home with follow-up advice or support referrals.

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How alcohol affects your brain and behaviour

When you drink, alcohol goes into your bloodstream and heads straight for your brain, changing how you feel and behave. It affects neurotransmitters like dopamine and serotonin, which make you feel good and encourage more drinking. It also affects GABA and glutamate, which regulate brain activity and keep you safe.

How alcohol changes your brain

Quick drinking causes levels to rise fast, increasing the risk of overdose. Women often experience effects more quickly due to body size and metabolism differences.

Common behaviour changes when drinking

Violence: Alcohol affects judgment and restraint, making aggression more likely
Slurred speech: Impaired muscle control leads to slurring and slower reaction times
Trips and falls: Alcohol slows coordination and balance, increasing injury risk
Risky sex: Lower inhibitions and poor judgment can increase unsafe sex or difficulty with consent
Sleepiness: Alcohol is a central nervous system depressant, making you sleepy but disrupting sleep quality
Blackouts: Drinking heavily can block memory formation in the hippocampus, causing gaps or total amnesia

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Mixing alcohol with other drugs

Mixing alcohol with drugs is dangerous. Both pass through the liver, increasing harmful effects and creating toxic substances. It also increases overdose risk.

Stimulants

Cocaine, speed, ecstasy, mephedrone: These speed up heart rate while alcohol slows it down. Mixing them puts your heart and brain under extreme pressure. Alcohol with cocaine produces cocaethylene, which increases heart attack or stroke risk.

Depressants

GHB, GBL: Both cause sleepiness and loss of consciousness. Combined with alcohol, the risk of coma or death rises sharply.
Heroin, opioids: Powerful sedatives. Mixing even small amounts with alcohol can lead to fatal overdose.
Spice/synthetic cannabinoids: Very potent, unpredictable depressants. Mixing with alcohol increases overdose risk.

Prescription medicines

Antidepressants: Alcohol can worsen side effects and make you feel more depressed. With MAOIs it can dangerously raise blood pressure.
Tranquilisers: Medicines like diazepam, temazepam and lorazepam slow breathing and heart rate. Mixing with alcohol can be deadly.

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Safer drinking tips

These tips can help reduce the chances of drinking leading to an emergency.

Before you go out

Eat beforehand to help absorb alcohol. Set a limit on how much you'll drink.
Be careful with pre-drinking (or "pre-loading") — drinking a lot before going out can mean you start the night at a higher risk level and may lose track of how much you've had.

While you're drinking

Alternate with water or soft drinks to stay hydrated.
Avoid rounds to control your intake. Miss a round or choose low-alcohol options.
Drink slowly to give your body time to deal with the alcohol. The slower you drink, the easier it is for your liver to keep up and reduce the risk of alcohol building to dangerous levels.
Put your drink down between sips — if you hold your drink the whole time, you're more likely to drink faster without realising.

Know your drink's strength

Different drinks have different amounts of alcohol. You can check the label for the ABV (alcohol by volume) — this tells you what percentage of the drink is pure alcohol. The higher the number, the stronger the drink.

Your body can only process about one unit of alcohol per hour. If you drink too quickly, alcohol builds up in your system, which increases the risk of harm.

There's now a wide range of low and no alcohol drinks, including beers, wines, and spirits. In the UK, drinks with 1.2% ABV or less are classed as low alcohol, and drinks with 0.5% or less are often called alcohol-free.

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