Hangover symptoms typically include fatigue, headache, nausea, thirst, muscle aches, and sensitivity to light and sound. They begin as your blood alcohol level drops toward zero, usually peaking about 14 hours after you started drinking, and can last roughly 12 hours from the time you wake up. While most people recognize the basics, hangovers affect nearly every system in your body, and some symptoms catch people off guard.
The Full List of Symptoms
The National Institute on Alcohol Abuse and Alcoholism identifies a broad range of hangover symptoms: fatigue, weakness, thirst, headache, muscle aches, nausea, stomach pain, vertigo, sensitivity to light and sound, anxiety, irritability, sweating, and increased blood pressure. Most people experience a handful of these at once rather than all of them.
Some symptoms get less attention than they deserve. Vertigo, for instance, can make the room feel like it’s tilting when you stand up. Increased blood pressure and sweating are common but often blamed on poor sleep or dehydration alone. And many people don’t realize that the clumsiness and mental fog they feel the next day are recognized hangover symptoms, not just tiredness. Researchers use a standardized scale that includes items like apathy, dizziness, and reduced coordination alongside the more obvious complaints.
Why You Feel This Way
A hangover isn’t one problem. It’s several overlapping ones.
Alcohol suppresses a hormone that tells your kidneys to hold onto water. The result is that you urinate far more than the volume of liquid you took in, which drives the thirst, dry mouth, and headache. At the same time, alcohol irritates the stomach lining and increases acid production, which explains the nausea and stomach pain.
Your immune system also plays a larger role than most people realize. During a hangover, levels of certain immune signaling molecules rise significantly compared to normal. This immune response is closely linked to nausea, headache, diarrhea, and fatigue, similar to the general achiness you feel when fighting off an infection. That “hit by a truck” feeling isn’t just from poor sleep. It’s your body mounting an inflammatory response.
Hangover Anxiety Is Real
If you’ve ever woken up after drinking with a sense of dread or racing thoughts, you’re experiencing what’s sometimes called “hangxiety.” This isn’t just guilt about the night before. It has a neurochemical basis.
While you’re drinking, alcohol activates the brain’s calming system (GABA receptors) and simultaneously suppresses the system that generates alertness and anxiety (glutamate). You feel relaxed and uninhibited. But as alcohol wears off, your brain overcorrects. It dials down the calming signals and ramps up the excitatory ones, leaving you in a state that’s the mirror image of how you felt while drinking: jittery, anxious, and on edge. For people who already deal with anxiety, this rebound effect can be especially intense.
How Long a Hangover Lasts
Hangover symptoms typically start increasing about 8 hours after drinking, as your blood alcohol level approaches zero. They tend to peak around 14 hours after you began drinking. For most people, that peak lands somewhere around 8 in the morning after a night out.
From the time you stop drinking, the average total duration is about 18 hours, though most people fall in a range of 14 to 23 hours. From the time you actually wake up and notice the symptoms, expect roughly 12 hours before they fully clear. That means a hangover that greets you at 8 a.m. may not fully lift until the evening. Hangovers from heavier drinking sessions tend to sit at the longer end of that window.
Why Some Drinks Cause Worse Hangovers
Not all alcohol hits the same way the next morning. The culprits are congeners, byproducts created during fermentation and distillation that give drinks their flavor, color, and aroma. Darker, more complex drinks contain more of them.
Red wine, brandy, and whiskey have the highest concentrations of methanol, one key congener. Beer and vodka have the lowest. In controlled studies, people who drank bourbon reported significantly worse hangovers than those who drank the same amount of vodka, reaching the same peak blood alcohol level. Vodka drinkers consistently report milder symptoms than whiskey drinkers at equivalent doses.
That said, congeners aren’t the whole story. One study found that methanol levels in urine correlated specifically with vomiting but not with overall hangover severity. The amount of alcohol you drink still matters far more than the type. Switching to vodka won’t save you if you drink twice as much of it.
Hangover vs. Alcohol Poisoning
Most hangovers are miserable but not dangerous. Alcohol poisoning is a medical emergency, and the distinction matters because poisoning symptoms can appear while someone is still drinking or shortly after they stop, before a typical hangover would even begin.
The key differences:
- Confusion: Mild brain fog is normal with a hangover. Severe confusion where someone doesn’t recognize their surroundings or can’t respond coherently signals poisoning.
- Breathing: Slow or irregular breathing, especially fewer than eight breaths per minute, does not happen with a standard hangover. This is a red flag.
- Consciousness: A hungover person can be woken up. Someone with alcohol poisoning may be completely unresponsive.
- Skin color: Pale or blue-tinged skin indicates the body isn’t getting enough oxygen.
- Vomiting: Occasional nausea is a hangover symptom. Severe, uncontrollable vomiting, especially in someone who is semi-conscious, creates a choking risk and points to poisoning.
Seizures are another sign of alcohol poisoning that never occur with a routine hangover. If someone shows any combination of severe confusion, irregular breathing, unresponsiveness, or bluish skin, that’s not a bad hangover. It requires emergency medical attention immediately.