Most hangovers last about 24 hours, though they can stretch longer depending on how much you drank, what you drank, and your individual biology. Symptoms typically peak once your blood alcohol level drops back to zero, which for a heavy night of drinking usually means the worst hits the morning after and fades by evening. But some hangovers, especially after binge drinking, can linger into a second day.
The Typical Hangover Timeline
A hangover doesn’t actually start while you’re still drunk. Symptoms begin as alcohol leaves your system and peak once your blood alcohol concentration returns to approximately zero. For most people, that means waking up feeling terrible the morning after drinking and gradually improving over the next 12 to 20 hours.
The early hours tend to be the worst: headache, nausea, fatigue, and sensitivity to light and sound. By the afternoon or evening, most people are feeling significantly better. The full cycle from first symptom to relief typically falls within that 24-hour window, though you may feel slightly “off” for a bit longer, with residual fatigue or a foggy head carrying into the next morning.
Why Some Hangovers Last Two Days
If you’ve ever had a hangover that stretched well past 24 hours, several factors are likely at play. The amount of alcohol is the most obvious one: more alcohol means more of its toxic byproduct, acetaldehyde, needs to be processed by your liver. Your body breaks alcohol down in two steps. First, enzymes convert alcohol into acetaldehyde, a compound that’s significantly more toxic than alcohol itself. Then a second set of enzymes converts acetaldehyde into harmless substances your body can flush. When you drink heavily, that second step can’t keep pace, and acetaldehyde builds up. This buildup is considered a major driver of hangover symptoms, and clearing it simply takes longer after a big night.
Sleep disruption also extends the misery. Alcohol initially makes you drowsy, but as it leaves your system, your brain rebounds into a state of heightened excitability. This is why you might fall asleep easily after drinking but wake up at 3 or 4 a.m. feeling wired and anxious. That poor-quality sleep compounds the fatigue and brain fog, making the hangover feel like it drags on well into a second day even after the direct chemical effects have faded.
What Causes “Hangxiety”
That wave of anxiety and unease that hits during a hangover has a neurological explanation. Alcohol enhances the activity of your brain’s calming system while suppressing its excitatory signals. When the alcohol wears off, the balance flips: your brain’s stress-response system goes into overdrive, while the calming mechanisms are still dialed down. The result is a jittery, anxious feeling that can last most of the day. This rebound effect also contributes to the racing heart, restlessness, and irritability many people experience alongside the more familiar headache and nausea.
Dark Liquors Make It Worse
Not all drinks produce equal hangovers. Dark-colored alcohols like bourbon, whiskey, and red wine contain higher levels of congeners, which are chemical byproducts of fermentation. These congeners contribute to both the severity and the number of hangover symptoms you experience. Research comparing bourbon drinkers to vodka drinkers found that bourbon, a high-congener liquor, produced noticeably worse hangovers than vodka, which contains very few congeners. If you’re trying to minimize your recovery time, lighter-colored spirits and white wine are a better bet, though the total amount of alcohol you consume still matters far more than the type.
Dehydration Alone Isn’t the Whole Story
Drinking water is good advice, but it won’t prevent or cure a hangover on its own. Research has found that while dehydration effects from alcohol tend to be mild and short-lived, hangover symptoms are relatively enduring by comparison. The bulk of what makes you feel terrible comes from your body’s inflammatory response to alcohol and the toxic byproducts of its metabolism, not simply from fluid loss. Rehydrating helps with dry mouth, thirst, and mild headache, but it won’t touch the nausea, anxiety, or fatigue driven by deeper biochemical processes.
Why Hangovers Get Worse With Age
If hangovers seem harder to shake than they used to be, your biology is genuinely changing. The liver enzymes responsible for breaking down alcohol and clearing acetaldehyde become less active as you age. At the same time, your body’s total water volume decreases, which means the same number of drinks produces a higher blood alcohol concentration than it would have a decade earlier. The combination of slower metabolism and higher effective doses means alcohol is more toxic to your system with each passing year. Your brain and liver also become more sensitive to alcohol’s effects over time, so recovery takes longer even from moderate drinking.
Hangover vs. Alcohol Withdrawal
A hangover and alcohol withdrawal can look similar in the early stages: headache, anxiety, insomnia, shakiness. The difference comes down to drinking patterns. A hangover happens to anyone after a night of heavy drinking and resolves within a day or so. Alcohol withdrawal is a medical condition that occurs in people who drink heavily and regularly, then suddenly stop or sharply cut back. Withdrawal symptoms can begin within 6 to 12 hours of the last drink and may escalate over the following days rather than improving.
The threshold for heavy drinking that puts someone at risk for withdrawal is lower than many people assume: five or more drinks on any day for men (or 15 or more per week), and four or more on any day for women (or 8 or more per week). If your “hangover” symptoms are getting progressively worse, include tremors or confusion, or last well beyond 48 hours, that pattern may point to something beyond a standard hangover.