A hangover, also known as veisalgia (vy-SAL-gee-uh), occurs after a person becomes intoxicated from drinking too much alcohol. Hangovers may have several unpleasant symptoms, including headache, sensitivity to sound, jitteriness, tiredness, and nausea.

What Is a Hangover?

When individuals drink too much alcohol, they may wake up the next morning with a hangover. Generally, the more alcohol they drink, the worse their hangover is and the longer it lasts. The amount of alcohol that brings on a hangover varies from person to person. The amount of alcohol that causes a hangover in a person who is a light drinker may not cause one in a person who is a frequent, heavy drinker. Frequent and heavy drinkers develop a tolerance to alcohol.

However, heavy alcohol consumption can lead to many serious health problems. In the near term, alcohol poisoning is a drug overdose, which can lead to persistent vomiting, changes in mental status, coma * , and death. Over the long term, heavy drinking can lead to cirrhosis * of the liver, which can be fatal.

Regular consumption of alcohol can also lead to alcoholism, a progressive long-lasting dependency on alcohol. Alcoholics have a physical craving for alcohol. Chronic alcohol consumption can lead to many health and other problems. Alcohol consumption can affect people's work life, their finances, and their relationships with family and friends. Habitual drinkers who drive are likely to experience legal problems with traffic tickets or accidents. They may lose their license to drive. The court can order them to attend driver responsibility sessions or attend meetings of Alcoholics Anonymous. The best way to prevent alcoholism is to avoid drinking alcohol or to drink infrequently and only in small amounts. Restricting alcohol consumption avoids a lot of potential problems, and it prevents having a hangover the morning after.

What Are the Symptoms of Hangover?

Typically, hangover symptoms begin a few hours after individuals stop drinking, often beginning the following morning and continuing for several hours. Symptoms may include one or more of the following:

People with a hangover may feel strongly repulsed by the mere thought of alcohol.

What Causes a Hangover?

A hangover is related to the hormone vasopressin (vay-zo-PRESS-in). Drinking alcohol puts alcohol into the bloodstream. The alcohol releases the antidiuretic hormone from the posterior pituitary gland. Normally, vasopressin signals the kidneys to send water back into the body where it can be used. When alcohol blocks vasopressin production, however, the kidneys send most of the water to the bladder, which then releases it as urine. This water comes from the body itself as well as from the alcoholic beverage. In fact, drinkers' bodies release up to four times more water than is present in the beverages they consume. For this reason, people who are drinking alcoholic beverages urinate frequently.

The water imbalance causes many of the symptoms of a hangover. Some of these occur because urine releases both sodium and potassium, along with water. When the body loses too much sodium and potassium, its muscles and nerves do not function correctly. This dysfunction results in headaches, tiredness, and nausea. In addition, alcohol-induced water loss can cause a dry mouth.

Besides its effects on vasopressin and the subsequent water loss, alcohol also affects the liver. The liver regulates blood sugar, the body's primary fuel. Blood sugar is also known as glucose (GLUE-cose). The liver regulates glucose by storing some of it in a slightly different form, called glycogen (GLY-co-jen). When individuals drink alcohol, the alcohol breaks down the glycogen in the liver and converts it into glucose, but instead of moving the glucose into the bloodstream for the body's cells to use, the glucose goes into the urine and leaves the body. This reduces the amount of energy available to the body and causes hangover symptoms such as fatigue, general weakness, and poor coordination.

In addition, most alcoholic beverages contain congeners, which are substances that are generally added for flavor or color. Certain types of alcohol contain higher amounts of congeners, which may contribute to hangover symptoms. Dark liquors, such as brandy and whiskey, have more congeners than clear ones, such as vodka and gin.

Can Hangovers Be Prevented?

Avoiding alcohol is the surest way to prevent hangovers. People who do drink can also avert hangovers by taking certain steps. One way is to drink only on a full stomach or with food, to drink slowly, and to consume moderate amounts of alcohol. Drinking several eight-ounce glasses of water prior to going to sleep may help relieve dry mouth and dehydration * . The National Institute on Alcohol Abuse and Alcoholism recommends a maximum of one drink per day for women and two per day for men. The institute defines one drink as a 12-ounce beer, a 4-ounce glass of wine, or a mixed drink with 1.5 ounces of liquor (80-proof distilled spirits). Another suggestion is to drink a glass of water after every alcoholic beverage. Doing so helps to replace some water loss, to reduce dehydration, and to limit the amount of alcohol consumed by exchanging some of those alcoholic drinks with glasses of water. Finally, choosing alcohol with lower congener content may also help to prevent hangover.

How Is Hangover Treated?

Frequently recommended hangover treatments include:

When treating a hangover, some people take aspirin for headache. They should not, however, take acetaminophen * , which appears in many over-the-counter pain medications and which in the presence of alcohol can be harmful to the liver. People who are frequent, heavy drinkers should avoid acetaminophen at all times. The National Institute on Alcohol Abuse and Alcoholism also cautions that people who are taking any medications should talk to a doctor or pharmacist before drinking alcohol, because many medications interact harmfully with alcohol and can result in increased risk of illness, injury, or death. The institute also notes that many medications can make a person more susceptible to the effects of alcohol, so drinking while taking these drugs may be dangerous.

See also Alcoholism • Cirrhosis of the Liver


Books and Articles

Adams, Sally. “Hangover Severity May Be Partly Genetic.” Guardian, December 12, 2014. http://www.theguardian.com/science/siftingthe-evidence/2014/dec/12/hangover-severity-genetic-alcohol-inherited (accessed July 15, 2015).

Stromberg, Joseph. “Your Complete Guide to the Science of Hangovers.” Smithsonian. December 31, 2013. http://www.smithsonianmag.com/science-nature/your-complete-guide-to-the-science-of-hangovers-180948074/?no-ist (accessed July 15, 2015).

Swift, Robert, and Dena Davidson. “Alcohol Hangover Mechanisms and Mediators.”Alcohol Health and Research World 22, no. 1 (1998): 54–60. http://pubs.niaaa.nih.gov/publications/arh22-1/54-60.pdf (accessed July 15, 2015).


MedlinePlus. “Hangover Treatment.” U.S. National Library of Medicine. https://www.nlm.nih.gov/medlineplus/ency/article/002041.htm (accessed July 15, 2015).


National Institute on Alcohol Abuse and Alcoholism. 5635 Fishers Ln., MSC 9304, Bethesda, MD 20892-9304. Telephone: 301-443-3860. Website: http://www.niaaa.nih.gov (accessed July 15, 2015).

* coma (KO-ma) is an unconscious state, like a very deep sleep. A person in a coma cannot be awakened, and cannot move, see, speak, or hear.

* cirrhosis (sir-O-sis) is a condition that affects the liver, involving long-term inflammation and scarring, which can lead to problems with liver function.

* dehydration (dee-hi-DRAY-shun) is a condition in which the body is depleted of water, usually caused by excessive and unreplaced loss of body fluids, such as through sweating, vomiting, or diarrhea.

* acetaminophen (uh-see-teh- MIH-noh-fen) is a medication commonly used to reduce fever and relieve pain.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)