Most hangovers last up to 24 hours, though some can stretch longer depending on how much you drank, what you drank, and your body’s individual chemistry. Symptoms typically begin as your blood alcohol level drops and peak right around the time it hits zero, which for most people means the worst of it hits the morning after a night of heavy drinking.
The General Timeline
A hangover follows a fairly predictable arc. Symptoms start as your body finishes processing the alcohol in your system, usually several hours after your last drink. They peak when your blood alcohol concentration returns to roughly zero. For someone who stopped drinking at midnight, that peak often lands somewhere between early and mid-morning.
From there, symptoms gradually taper. The Mayo Clinic and the National Institute on Alcohol Abuse and Alcoholism both describe most hangovers as resolving within 24 hours. That said, “most” is doing real work in that sentence. A mild hangover from a few extra glasses of wine might fade by lunchtime. A severe one after a long night of heavy drinking can leave you feeling off well into the next day, and in some cases, residual fatigue, brain fog, or stomach upset can linger for 48 hours or more.
Why Some Hangovers Last Longer
The biggest factor is simply how much you drank. More alcohol means more toxic byproducts for your liver to clear, more dehydration, and a bigger inflammatory response throughout your body. During a hangover, levels of inflammatory markers like IL-6 and C-reactive protein rise measurably in your blood and saliva. These markers return to normal once the hangover resolves, but the more intense the episode, the longer that cleanup takes.
What you drank matters too. Darker spirits like bourbon, whiskey, and red wine contain far higher levels of congeners, which are chemical byproducts of fermentation. Bourbon contains roughly 37 times the congeners found in vodka. One of those congeners, methanol, lingers in the body after the main alcohol (ethanol) has been cleared. Your body then breaks methanol down into formaldehyde and formic acid, both highly toxic, which can extend and worsen hangover symptoms. In a controlled study, volunteers who drank bourbon reported significantly worse hangover scores the next morning compared to those who drank the same amount of alcohol as vodka.
Whether you ate before drinking also plays a role. Food in your stomach, especially fatty food, slows the rate at which alcohol enters your bloodstream. This doesn’t change how fast your liver processes alcohol once it’s absorbed, but it can reduce the spike in blood alcohol that leads to worse hangovers. Protein helps keep blood sugar stable, which tends to dip after drinking and contributes to that shaky, weak feeling the next day.
How Your Body Processes Alcohol
Your liver breaks alcohol down in stages. First, it converts ethanol into a compound called acetaldehyde, which is toxic. Then a second enzyme converts acetaldehyde into harmless substances your body can eliminate. The speed of that second step is the bottleneck. If your body clears acetaldehyde quickly, you tend to recover faster. If it doesn’t, the toxic compound builds up, and hangover symptoms get worse and last longer.
This is partly genetic. Some people are born with a less active version of the enzyme responsible for clearing acetaldehyde. This variation is particularly common in people of East Asian descent and is the same genetic trait that causes facial flushing after drinking. People with this enzyme variant are significantly more susceptible to hangovers because their bodies simply can’t eliminate acetaldehyde efficiently.
Why Hangovers Get Worse With Age
If you’ve noticed hangovers hitting harder in your 30s, 40s, or beyond, you’re not imagining it. Your liver enzymes change as you age, slowing your body’s ability to break down alcohol. Everyone is born with varying levels of enzyme activity, but the liver becomes less resilient over time and doesn’t process alcohol as efficiently as it did when you were younger. The result is that the same amount of drinking produces a longer, more punishing recovery. A hangover that would have cleared by noon in your twenties might now stretch through the entire next day.
Body composition changes compound the problem. Older adults tend to carry less water and more body fat, which means the same number of drinks produces a higher blood alcohol concentration. Less water also means greater dehydration from the same amount of alcohol.
When It Might Not Be a Hangover
A hangover that seems to last well beyond 24 to 48 hours, or that includes symptoms like confusion, seizures, rapid heartbeat, or excessive sweating, could be something else entirely. Alcohol withdrawal is a distinct medical condition that affects people who drink heavily and regularly, then stop or sharply cut back. Withdrawal symptoms typically begin within 6 to 24 hours of the last drink, which can make them easy to confuse with a bad hangover, but they tend to escalate rather than gradually improve.
The key difference is trajectory. A hangover peaks and then slowly gets better. Withdrawal can get progressively worse over 24 to 72 hours and, in severe cases, becomes a medical emergency. Symptoms like slow or irregular breathing, blue or gray skin, seizures, or an inability to stay conscious require emergency care regardless of the cause.
What Actually Helps You Recover Faster
No food, supplement, or trick speeds up how fast your liver processes alcohol. That rate is essentially fixed. What you can do is manage the secondary damage: dehydration, electrolyte loss, low blood sugar, and inflammation.
Water and electrolytes address the dehydration component. Salty foods help your body retain fluids and replenish what you lost. Protein-rich meals help stabilize blood sugar. Sleep gives your body uninterrupted time to clear the remaining toxins. None of these will cut a hangover short, but they can reduce the severity of symptoms while your body does the work on its own timeline.
The most reliable way to shorten a hangover is to limit what causes it in the first place: drink less, choose lighter-colored spirits when possible, eat a substantial meal before drinking, and alternate alcoholic drinks with water throughout the night.