Ethanol poisoning, also called alcohol poisoning, happens when you drink more alcohol than your body can safely process, causing it to reach toxic levels in your bloodstream. The danger threshold is a blood alcohol concentration (BAC) above 0.31%, where you risk losing consciousness, stopping breathing, or falling into a coma. In the United States, alcohol-induced deaths reached 54,258 in 2021, though acute poisoning accounts for a smaller subset of that total.
How Ethanol Becomes Toxic
Ethanol is a central nervous system depressant. At low doses, it produces the familiar relaxation and lowered inhibitions of a couple of drinks. At high doses, it overwhelms the brain’s ability to regulate basic survival functions like breathing and temperature control.
The mechanism is straightforward: ethanol amplifies the activity of your brain’s primary “slow down” signaling system. Normally, this system keeps neural activity in balance, but ethanol forces it into overdrive, increasing both the frequency and strength of inhibitory signals between brain cells. At moderate levels, this produces slurred speech and poor coordination. At dangerous levels, it suppresses the brainstem circuits that keep you breathing.
Your body breaks down alcohol at a roughly fixed rate, typically eliminating about one standard drink per hour. When intake far exceeds that rate, ethanol accumulates in the blood and the toxic effects escalate predictably.
Symptoms at Each Stage
The severity of ethanol poisoning tracks closely with BAC. Knowing these stages helps you recognize when someone has crossed from drunk into dangerously poisoned.
- BAC 0.05% to 0.1%: Impaired judgment and coordination. The person may seem clumsy or make poor decisions but is still alert.
- BAC 0.1% to 0.2%: Unsteady walking, clearly slurred speech, mood swings, and noticeable behavior changes. This is the range of obvious intoxication.
- BAC 0.2% to 0.4%: Nausea and vomiting, double vision, involuntary eye movements, memory blackouts, and dropping body temperature. This is the danger zone where poisoning begins.
- BAC above 0.4%: Respiratory depression, coma, and death. The brain can no longer maintain the automatic drive to breathe.
These ranges overlap and vary between individuals. Someone with no tolerance can experience severe symptoms at lower concentrations than a chronic heavy drinker, though the lethal threshold remains dangerous for everyone.
Why Aspiration Is a Hidden Killer
One of the most dangerous complications of ethanol poisoning isn’t the alcohol itself. It’s choking on vomit. Your throat has a set of protective reflexes designed to keep stomach contents out of your lungs. When you’re severely intoxicated, ethanol suppresses these reflexes at the brain level. The muscle at the top of your esophagus, which normally tightens to block stomach contents from rising into your throat, stops responding properly. The swallowing reflex that would clear fluid from your airway also shuts down.
This is why someone who passes out from drinking and then vomits can inhale stomach acid into their lungs, leading to aspiration pneumonia or suffocation. It’s also why you should never leave a heavily intoxicated person lying on their back. Turning them on their side (the recovery position) can be lifesaving.
Metabolic Complications
Beyond the direct brain effects, ethanol poisoning triggers several metabolic problems that compound the danger. The most significant is low blood sugar. Ethanol interferes with your liver’s ability to produce glucose, which means your blood sugar can drop to dangerously low levels, especially if you haven’t eaten. Low blood sugar on its own can cause confusion, seizures, and loss of consciousness, making an already dangerous situation worse.
Body temperature also drops. Alcohol dilates blood vessels near the skin, which makes you feel warm while actually accelerating heat loss. Combined with impaired judgment that might leave someone passed out in cold weather, hypothermia becomes a real risk.
Why Children Are Especially Vulnerable
Infants and young children can develop life-threatening ethanol poisoning from surprisingly small amounts. A child who swallows a few ounces of mouthwash, hand sanitizer, or an unattended drink faces risks that would barely register in an adult. Blood concentrations as low as 50 to 100 mg/dL are considered toxic in children, and levels above 100 mg/dL can depress the central nervous system significantly.
Several biological factors explain this vulnerability. Children have far smaller glycogen stores in their livers, so their blood sugar crashes faster and harder. Newborns produce only about one-tenth the amount of the primary alcohol-metabolizing enzyme that adults do, meaning the alcohol lingers in their system much longer. Their low body mass also makes them prone to hypothermia. The combination of profound low blood sugar, slow alcohol clearance, and rapid heat loss makes pediatric ethanol poisoning a medical emergency even from doses that seem trivial.
What Happens at the Hospital
There is no antidote for ethanol poisoning. Treatment is supportive, meaning the medical team keeps you alive and stable while your body processes the alcohol. The first priority is always making sure you can breathe. If your airway is compromised, that gets addressed before anything else.
Because alcohol acts as a diuretic, dehydration is common, and intravenous fluids help restore fluid balance and maintain kidney function. If blood sugar is low, a sugar solution is given through the IV. People who appear malnourished or have been drinking heavily for an extended period typically receive thiamine (vitamin B1) to prevent a serious brain condition caused by thiamine deficiency.
Heart monitoring is standard for heavily intoxicated patients, since alcohol can affect heart rhythm. In most cases, the person is observed in a monitored setting until their BAC drops to a safe level and they can protect their own airway.
Recovery and Lasting Effects
For a single episode of severe intoxication, the prognosis is generally good if the person receives appropriate care and avoids the acute complications like aspiration or respiratory failure. Animal research suggests that even after a heavy binge episode, measurable brain changes, including swelling and shifts in brain chemistry, reverse within about seven days of abstinence. This points to transient rather than permanent damage from an isolated event.
That said, repeated episodes of heavy drinking carry cumulative risks. Alcoholic liver disease and long-term brain damage are well-documented consequences of chronic alcohol use. The demographic groups most affected by alcohol-induced deaths in the U.S. are adults aged 55 to 64 and American Indian and Alaska Native populations. Men die at higher rates than women, though the fastest-growing increase in alcohol-related deaths between 1999 and 2024 occurred among younger adults aged 25 to 34, with a 255% increase among women and 188% among men in that age group.
Recognizing an Emergency
The signs that someone has crossed from very drunk into poisoned include vomiting while unconscious or semiconscious, slow or irregular breathing (fewer than eight breaths per minute), skin that looks pale or bluish, a body temperature that feels cold to the touch, and an inability to be woken up. Seizures can also occur.
A person’s BAC can continue rising even after they stop drinking, because alcohol in the stomach and intestines is still being absorbed into the bloodstream. This means someone who seems “just really drunk” when they stop drinking can deteriorate significantly over the next 30 to 60 minutes. Waiting to see if they “sleep it off” is the most dangerous decision bystanders commonly make.