A hangover makes you feel terrible, but alcohol poisoning can kill you. The difference comes down to what your body is doing while you feel sick. Hangover symptoms appear after your blood alcohol level drops and are uncomfortable but not dangerous on their own. Alcohol poisoning symptoms happen while blood alcohol is still dangerously high and signal that your body’s basic functions, like breathing and temperature regulation, are shutting down.
How a Hangover Feels
Hangover symptoms typically start several hours after you stop drinking, often the next morning, as your body processes the remaining alcohol and deals with the aftermath. The most common signs include a throbbing headache, nausea, sensitivity to light and sound, fatigue, muscle aches, and thirst. You might also feel dizzy, irritable, or unable to concentrate. These symptoms peak when your blood alcohol level returns to zero and generally resolve within 24 hours.
The underlying causes are straightforward. Alcohol is a diuretic, so you lose more fluid than you take in, which leads to dehydration and headache. It irritates your stomach lining, causing nausea. It disrupts your sleep cycles, leaving you exhausted even after a full night in bed. And as your body breaks down alcohol, it produces a toxic byproduct called acetaldehyde that contributes to the overall misery before being cleared from your system.
A hangover feels awful, but throughout all of it, you’re conscious, breathing normally, and responsive. That distinction matters.
Symptoms of Alcohol Poisoning
Alcohol poisoning is a medical emergency. It happens when you drink so much that alcohol overwhelms your body’s ability to process it, and your blood alcohol concentration climbs to a level that suppresses the brain’s control over vital functions. At a blood alcohol level of 0.30% to 0.40%, you’re likely experiencing alcohol poisoning and loss of consciousness. Above 0.40%, there is a real risk of coma and death from respiratory failure.
The warning signs are distinct from a hangover:
- Slow breathing: fewer than 8 breaths per minute
- Irregular breathing: gaps of 10 seconds or more between breaths
- Confusion or stupor: far beyond typical drunkenness
- Inability to speak or coordinate movement: unable to stand, walk, or pick things up
- Vomiting while semi-conscious or unconscious
- Seizures
- Pale, bluish, or cold skin: on darker skin tones, look for color changes inside the lips, on the gums, and under the fingernails
- Loss of consciousness that you can’t wake them from
- Loss of bladder or bowel control
The key difference is responsiveness. A person with a bad hangover can talk to you, sit up, and tell you how they feel. A person with alcohol poisoning may not respond to shaking, shouting, or pain. Their body is in a state of suppression, not recovery.
Why Alcohol Poisoning Is Dangerous
Alcohol is a central nervous system depressant. In large amounts consumed rapidly, it suppresses the brain regions that control breathing, heart rate, and body temperature. This is what makes it lethal, not liver damage or dehydration, but the brain losing its ability to keep the body’s basic systems running.
One of the most immediate dangers is choking. Alcohol suppresses the gag reflex, meaning a person who vomits while semi-conscious or unconscious can inhale vomit into their lungs. This aspiration is one of the most common reasons people die from alcohol overdose. Even if someone survives the aspiration, bacteria from the throat and mouth can enter the lungs and cause pneumonia or other serious infections.
Hypothermia is another risk that often gets overlooked. Alcohol dilates blood vessels near the skin, which makes you feel warm while actually accelerating heat loss. A person with alcohol poisoning can develop dangerously low body temperature, especially if they’ve passed out in a cold environment. Blood sugar can also drop to dangerous levels during severe intoxication, and this hypoglycemia can cause seizures on its own.
Even people who have built up a high tolerance to alcohol’s effects on mood and coordination can still die from respiratory depression. Tolerance does not protect the brainstem from shutting down.
The Gray Zone Between Hangover and Emergency
The trickiest situation is when someone seems like they’re “just really drunk” and you’re not sure if they’ve crossed the line. Blood alcohol can continue rising for 30 to 40 minutes after the last drink, so someone who seems okay when they stop drinking can deteriorate quickly.
A few practical rules help clarify things. If the person can hold a conversation, even a sloppy one, and is breathing normally, they’re likely intoxicated but not in immediate danger. If they’re unresponsive, breathing irregularly, having seizures, or their skin looks pale or bluish, that’s alcohol poisoning. When in doubt, the safest assumption is to treat it as an emergency. People do not “sleep off” alcohol poisoning.
It’s also worth knowing that vomiting is not a reliable sign either way. A hungover person throws up because their stomach is irritated. A person with alcohol poisoning may vomit because the body is trying to expel the toxin, but the suppressed gag reflex means they can’t protect their airway while doing so. The same symptom carries completely different levels of risk depending on the person’s state of consciousness.
What to Do If You Suspect Alcohol Poisoning
Call emergency services immediately. While you wait, turn the person on their side so that if they vomit, they won’t choke. This is sometimes called the recovery position. Cover them with a blanket to help prevent hypothermia. Stay with them and keep them on their side, even if they seem stable.
Talk to the person and explain what you’re doing. Someone in a confused, semi-conscious state may become agitated or combative if they don’t understand why they’re being moved or held in place. When paramedics arrive, be ready to describe how much the person drank, over what time period, and whether they took any other substances. This information helps guide treatment.
Do not try to make the person vomit, give them coffee, put them in a cold shower, or let them “walk it off.” None of these folk remedies address the central problem, which is that alcohol is suppressing their brain’s ability to keep them alive. The only effective intervention is professional medical care.
Why Timing Matters
A hangover begins after the danger has mostly passed. Your body has already metabolized much of the alcohol, and while you feel miserable, your vital signs are stable. Alcohol poisoning is happening in real time, while the alcohol is still active in your bloodstream and still suppressing brain function. The window between “very drunk” and “medical emergency” can be narrow, sometimes just a few drinks consumed quickly on top of an already high blood alcohol level.
Binge drinking is the most common cause. Consuming a large amount of alcohol in a short period, particularly on an empty stomach, can push blood alcohol levels into the danger zone before the person even feels the full effect of what they’ve already consumed. The body metabolizes roughly one standard drink per hour, so drinking faster than that means blood alcohol keeps climbing with each additional drink.