Alcohol: Facts, Effects and Health Risks


MNT Knowledge Center

Alcohol, or ethanol, is a sedative, hypnotic drug, and the intoxicating ingredient present in wine, beer, and spirits.  It is produced by the fermentation of yeast, sugars, and starches found in different foods.

Alcohol is a legal recreational substance for adults, but it is commonly misused among individuals of all ages, resulting in significant health, legal and socio-economic damage. The effects of alcohol are particularly harmful to adolescents and unborn babies.

Alcohol is one of the most commonly used drugs in the US, and the World Health Organization (WHO) estimate that alcohol dependence is the third leading cause of disease burden in developing countries worldwide. An overdose of alcohol can lead to severe central nervous depression, with progression to coma or death.

Contents of this article:

  1. What is alcohol?
  2. Side effects, health risks

Fast facts on alcohol

Here are some key points about alcohol. More detail and supporting information is in the main article.

  • Pure alcohol is a colorless, odorless and flammable liquid
  • Fruits (grapes and apples) and grains (barley and wheat) are the most commonly used foods to make alcohol
  • The legal age to drink, buy or sell alcohol in the United States is 21 years of age
  • Alcohol is the number one abused drug by minors in the US
  • Although it is classified as a sedative, hypnotic drug, it has a stimulant effect in small amounts
  • The liver can only oxidize about one drink per hour
  • Alcohol is known to be harmful to developing brains (from fetus to adolescence)
  • No amount of alcohol consumption can be considered safe during pregnancy
  • The effects of drinking and taking other medications – either over-the-counter or prescribed – can be unpredictable and potentially deadly
  • Roughly 1 in 10 deaths among working-age adults results from excessive drinking.

What is alcohol?

Ethyl alcohol (ethanol), the only alcohol used in beverages, is typically produced by the fermentation of grains and fruits. Two other alcohols, methyl alcohol (methanol) and isopropyl alcohol (isopropanol), are found in commercial products and are considered toxic to humans.

Fermenting is a chemical process whereby yeast acts upon certain ingredients in the food, creating alcohol. Records of fermented beverages can be traced back to early Egyptian civilizations. One of the first alcoholic beverages to gain popularity in Ancient Greece was mead, a fermented drink made from honey and water.

Bottles and glasses of alcoholic drinks.
Alcohol is often consumed in the form of beer, wine and spirits.

The most commonly consumed alcoholic beverages are beer, wine, and spirits.

Beer is brewed by malting, mashing, fermenting and aging grains (mainly barley). Flowers known as “hops” and other spices are added for flavor and balance. The alcohol content of beer averages 5%. One 12 oz beer is the equivalent of one “drink.”

Wine is made by first fermenting and then aging different varieties of grapes. The alcohol content of wine varies from around 9% to 20%. A 5 oz serving of a 12% alcohol-content wine is the equivalent of one “drink.”

Spirits are a product of both fermentation and distillation. This results in a much higher alcohol content of between 20% and 40%. A 1.5 oz measure of 80-proof spirits – a shot – is the equivalent of one “drink.” Examples of spirits include vodka, gin, whiskey and rum.

Within minutes of ingesting alcohol, it is absorbed into the bloodstream by blood vessels in the stomach lining and small intestine. The alcohol then travels to the brain where it quickly produces its effects. Drinking with a meal slows the rate of this absorption, resulting in fewer side effects and less intoxication.

Approximately 20% of alcohol is absorbed through the stomach; most of the remaining 80% is absorbed through the small intestine. Approximately 5% of the alcohol taken into the body leaves through the lungs, kidneys and the skin; the rest is removed by the liver.

Alternative names for alcoholic drinks

  • Booze
  • Grog
  • Liquor
  • Charge
  • Nip
  • Bottle
  • Firewater
  • Hooch
  • Juice
  • Moonshine
  • Sauce
  • Strong drink
  • Tipple
  • Chaser
  • Nightcap
  • Nappy
  • Toddy
  • Red eye
  • Chug
  • Cold one
  • Hard stuff
  • Jack
  • Mouthwash
  • Swish
  • Vino.

Extent of alcohol use

Crashed car at the side of a road.
Nearly a third of driving fatalities in the US in 2013 were due to alcohol consumption.

The 2013 National Survey on Drug Use and Health (NSDUH) recorded 8.7 million people ages 12-20 (22.7%) reporting drinking alcohol in the past month.

Additionally, 86.8% of people ages 18 or older reported that they drank alcohol at some point in their lifetime; 70.7% reported that they drank in the past year; 56.4% reported that they drank in the past month.

Alcohol-impaired driving fatalities accounted for 10,076 deaths (30.8% of overall driving fatalities).

Alcohol contributes to a high burden of disease in society in terms of years that people spend with disability or in poor health because of alcohol-related illnesses or injuries.

On the next page, we look at the side effects, health risks and withdrawal symptoms of alcohol consumption.


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Side effects of alcohol

Depending on how much is consumed, along with the weight and sex of the individual, alcohol has various side effects. Initially, alcohol makes a person feel relaxed, uninhibited or giddy. As a person consumes more alcohol, intoxication or drunkenness may result.

Signs of intoxication include:

  • Slurred speech
  • Unsteady walk
  • Drowsiness
  • Vomiting
  • Headache
  • Distortion of senses
  • Blacking out.

Intoxication impairs judgment and can result in inappropriate and illegal behaviors such as sexual promiscuity, disorderly conduct, driving while intoxicated and acts of violence.

After a night of heavy drinking, a person may continue to feel the effects of the alcohol with what is commonly called a “hangover.” Symptoms of a hangover include headaches, diarrhea, nausea, fatigue, racing heart, dry mouth and eyes, difficulty concentrating, and restlessness.  A hangover can last up to 24 hours.

The most serious side effect of alcohol consumption is respiratory and central nervous system depression. When the amount of alcohol in the blood exceeds a certain level, or if other depressant-type medications are taken in combination, the respiratory system significantly slows down, resulting in a lack of oxygen to the brain. This can quickly progress to a comatose state and eventual death.

Withdrawal symptoms

Alcohol consumption can lead to tolerance (body requires more alcohol to achieve the desired effect), dependency (body adapts to the presence of the drug and withdrawal occurs if the drug is suddenly stopped) and can progress to alcoholism (addiction to alcohol).

A woman is drinking at work.
People who are addicted to alcohol are unable to stop drinking without experiencing withdrawal symptoms.

Alcoholism is a disease characterized by a strong craving for alcohol, and continued use despite negative consequences to one’s health, interpersonal relationships or ability to work. Individuals who suffer from dependency or alcoholism cannot just stop drinking without experiencing withdrawal symptoms.

Signs and symptoms of withdrawal generally occur between 4 and 72 hours after the last drink or after a reduction in drinking amounts, peak at about 48 hours and may last up to 5 days.

Withdrawal symptoms may include mild tremors, insomnia, anxiety and depressed mood. Most often, an individual takes a drink to stop the discomfort of withdrawal.

The most serious consequence of withdrawal is a medical emergency known as Delirium tremens, or “the DTs.” This condition involves body tremors (shaking), hallucinations or changes in mental status, confusion, extreme sleepiness and seizures that can result in death.

In order to prevent Delirium tremens, individuals with an alcohol dependency disorder who desire to stop drinking should seek professional medical care or a treatment center specializing in safe alcohol detoxification.  

Health risks of alcohol

Alcohol contributes to over 200 diseases and injury-related health conditions including dependence and addiction, liver cirrhosis, cancers, and unintentional injuries such as motor vehicle accidents, falls, burns, assaults and drowning.

Close to 100,000 people die from alcohol-related causes annually in the US, making it the third leading preventable cause of death.

Long-term alcohol misuse is associated with liver and cardiovascular disease, stomach ulcers, cancer, brain and nerve damage, vitamin deficiencies and mental health problems such as anxiety and depression.  

Treatment for alcoholism

The treatment of alcoholism involves a variety of interventions and requires medical, social and family support.

Individual and group counseling, medication (Antabuse, Naltrexone and Campral) and participation in support networks such as Alcoholics Anonymous are all options for overcoming addiction to alcohol. A detoxification program in a hospital or medical facility is another option for those who need that particular level of care.

Recent developments on alcohol from MNT news

Economic uncertainty drives employees to drink outside of work

Past research has demonstrated that individuals who lose their jobs during periods of economic uncertainty are more likely to turn to alcohol in an attempt to ease their stress, or even just fill their time. But a new study finds that even those who keep their jobs through such periods may be more likely to hit the bottle.

Reduce alcohol consumption, say new guidelines

There is no justification to drink for health reasons, and consumption of any level of alcohol increases the risk of a range of cancers, according to new guidelines published by the UK’s Department of Health.

Binge drinking plus chronic alcohol use damages liver more than expected

During the holiday festivities, our alcohol consumption typically tends to increase. A new study, however, provides a word of caution, as it found that when combined with repeated binge drinking, chronic alcohol use damages the liver more than previously thought.

Alcohol is a sedative, hypnotic drug that, when consumed legally, safely and in moderation, will not generally cause any lasting psychological or physical harm. However, despite its social acceptance and legality for consumption by adults, alcohol remains an abused drug that has the potential to cause significant and irreparable damage to the health and welfare of individuals of all ages.

Related articles:

  • Moderate drinking: alcohol limits, benefits, risks
  • Hangovers: causes, symptoms and treatment
  • Alcohol poisoning: causes, symptoms and treatment
  • 10 health risks of chronic heavy drinking.