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A hangover from alcohol use is an extremely common condition that involves dehydration, headache, fatigue, low mood, anxiety, nausea, and vomiting.
What is a hangover?
A hangover from alcohol use is an uncomfortable constellation of symptoms that usually occur after an episode of heavy or binge drinking.
These symptoms include dehydration, depression, headache, anxiety, appetite suppression, difficulty concentrating, nausea, and sleepiness. The severity of a hangover is determined principally by the number of drinks taken but can also be affected by the type of alcohol used, the genetic makeup of an individual, and an individual's sex.
Hangovers resolve by themselves, usually by 24 hours after onset, however, drinking water and getting sleep can lessen some (but not all) of the symptoms of a hangover.
You will begin to feel better in a few hours. Rehydrating with fluids, most importantly water, and taking an over-the-counter pain medication like acetaminophen (Tylenol) or ibuprofen (Advil) will help with your symptoms.
Symptoms of a hangover
The symptoms of a hangover most commonly include:
- Decreased sense of well-being
- Dehydration: This can manifest as dry mouth, feeling dizzy, and feeling lightheaded when standing up.
- Low appetite
- Tremor (shaking)
Other symptoms affecting certain individuals include:
- Lack of concentration
- Poor cognitive or physical performance
- Light sensitivity
What causes a hangover?
A hangover is usually caused by excessive drinking (drinking to intoxication). The typical course of a hangover is that it begins after the symptoms of intoxication have worn off. A hangover is usually first apparent when the blood alcohol level begins to fall and peaks in severity once the level is 0 and all the alcohol has been metabolized. Hangovers are usually experienced the morning after a night of heavy drinking since you are not conscious of the hangover during sleep. A hangover typically completely dissipates 24 hours after it begins but can dissipate much sooner.
It is commonly believed that the symptoms of a hangover are produced primarily by dehydration, however, this has not been proven. A number of hormones and molecules are increased and decreased during the hangover state, which may explain how the symptoms of a hangover come about after alcohol and its metabolites are eliminated from the body. There is also a direct toxic effect of the alcohol itself, which is thought to contribute to hangover severity.
It is also commonly believed that hangovers get worse with age. This, however, has also never been proven in a study of hangover severity.
Predictors of hangover severity
Below, in order of importance, are the causes of a more severe hangover
- Number of drinks consumed
- Amount of sleep achieved
- Sex: Females have worse hangovers than males even when having the same relative number of drinks.
- Amount of water consumed: While drinking water does not prevent hangovers, it can lessen the degree of dehydration and dry mouth experienced.
- Type of alcohol: Twice as many drinks of beer are required to produce a hangover as compared to liquor or wine.
- Congener content of the drink: See below.
The effect of congeners
Alcohol that contains more "congeners" — substances that add the flavor and the color to a drink — produce more severe hangovers than alcohols that don't contain these substances. Below, in order of decreasing congener content, are a few examples:
- Red Wine
- White Wine
While congener content may affect hangover severity, it has never been demonstrated in a study that mixing drink types leads to a worse hangover, even though this is a popular belief.
Some people deficient in a protein called alcohol dehydrogenase 2 (ALDH2) may experience some symptoms similar to a hangover during intoxication. These symptoms include flushing, sweating, and an increased heartbeat. While this is not technically a hangover, it can feel like one.
Treatment options and prevention for hangover
The best treatment for a hangover is allowing time to pass. Hangovers typically self-resolve within 24 hours. Some additional treatments that may help are listed below.
- Rehydrate (drink water): Although drinking water will not cure a hangover, it may decrease the symptoms of dry mouth, dizziness, and lightheadedness.
- Get sleep: Sleeping when intoxicated is hard or impossible because alcohol interferes with normal sleep architecture. Getting as much sleep as possible at night and taking naps during the day may decrease some symptoms of hangovers.
In addition, symptom management can help alleviate the specific symptoms of a hangover. For example, if one is experiencing light sensitivity, then it may be helpful to wear sunglasses or stay away from lights. If one is experiencing dizziness, then it may be helpful to drink water and lay down or sit still for some time.
Eating snacks or small meals containing complex carbohydrates, such as whole wheat toast and crackers may help prevent the nausea and low blood sugar associated with a hangover.
The following treatments are very popular techniques thought to decrease the severity and/or length of a hangover but have not demonstrated a benefit in studies:
- Drinking coffee/tea with caffeine
- Eating a large meal
- Drinking more alcohol: Also known as the "hair of the dog" strategy.
- Pain relievers (aspirin, ibuprofen, Tylenol)
In addition, it has also never been shown in a study that age affects the severity of hangovers.
The single best prevention against the development of a hangover is to abstain from drinking completely. However, if you are going to drink, limiting the number of drinks you have decreases the chance you will experience a hangover. In addition, decreasing the number of drinks decreases the severity of the hangover if one is experienced.
As stated in the "Causes" section, certain alcohols have different hangover-causing properties based on their congener content. If you are particularly predisposed to hangovers, it may be worthwhile to experiment with alcohols that have low congener content, such as beer, vodka, and white wine. A good rule of them is that the lighter the spirit is, the fewer congeners it has.
In order to ward off the symptoms of dehydration following a hangover, it is good practice to drink non-alcoholic fluids. In addition, ensuring you have an adequate amount of time to sleep may decrease difficulty concentrating and fatigue the following day.
When to seek further consultation for hangover
A hangover from alcohol, while unpleasant, is not ordinarily a medically dangerous condition. However, if you have persistent nausea/vomiting or are severely dehydrated, you may require urgent medical attention. The signs of persistent nausea/vomiting are feeling nauseated for many hours along with multiple episodes of vomiting in which you cannot keep down any fluids. Dehydration symptoms include dizziness, lightheadedness, fast heartbeat, irritability, and fainting. If you feel too impaired to operate a vehicle, make decisions, etc., then it may be a good idea to wait a few hours until you feel capable of doing so.
Questions your doctor may ask to determine hangover
- Any fever today or during the last week?
- Are you sick enough to consider going to the emergency room right now?
- Have you been feeling more tired than usual, lethargic or fatigued despite sleeping a normal amount?
- Have you experienced any nausea?
- Have you lost your appetite recently?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
Elliot Stein is a second-year internal medicine resident at Vanderbilt University Medical Center, and he intends to sub-specialize in cardiovascular disease. He graduated magna cum laude with an undergraduate degree in molecular and cellular biology from Harvard College in 2013. He obtained his MD and Master of Science in Translational Research (MSTR) from the University of Pennsylvania Perelman School of Medicine in 2019. He stayed at the University of Pennsylvania to complete his internship year 2019-2020 at Pennsylvania Hospital. Elliot also served as an emergency medical technician (EMT) in two countries and three US states before beginning his medical career. He joined Buoy Health in 2018 because of its promise to use new technology to deliver higher quality medical information to anyone regardless of ability to access medical care.
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