Effects of Alcohol: What Happens Inside When You Take a Drink?

The effects of alcohol depend on multiple factors: how much you drink, how often, how long you’ve been drinking, and, most important, how your body processes alcohol.

effects of alcohol

The effects of alcohol range from cardiovascular to diabetes to liver issues.

© Ocusfocus - Dreamstime.com

For better or worse, alcohol has been part of our cultural history for thousands of years. America’s most commonly used drug brings pleasure to some, grief to others; health risks for most people, health benefits for a few. It’s not going away—in fact, a 2017 study estimated that one in eight Americans struggles with alcohol abuse. The study’s authors, according to JAMA Psychiatry make “a compelling case that the United States is facing a crisis with alcohol use, one that is currently costly and about to get worse.” So we need to understand what happens when a person chooses to drink alcohol.

Most of alcohol’s health risks are associated with heavy drinking or binge drinking. For men, heavy drinking means 15 or more drinks per week; for women, it’s eight or more drinks per week. Binge drinking for men is five or more drinks during a single session. For women, it’s four or more.

effects of alcohol

“Pick your poison,” as they say. While there may be cases where alcohol in moderation offers benefits, by and large, it can be problematical. A 2017 study shows one in eight Americans struggles with alcohol abuse. (Photo: Photo 32797366 © Draghicich – Dreamstime.com)

A Drink Defined

According to the Centers for Disease Control and Prevention, a drink is:

  • 12 ounces of beer
  • 8 ounces of malt liquor
  • 5 ounces of wine
  • 1.5 ounces of 80-proof gin, rum, vodka, or whiskey

Alcohol’s Effects on the Brain

Alcohol is a depressant. It slows things down and interferes with the brain’s pathways of communication. One or two drinks may make a person feel excited or more talkative, but it doesn’t take much more alcohol for that same person to become more sedated and less coordinated, and to experience impaired thinking and memory.

The University of West Virginia gives this preview of what might happen:
Having the number of drinks listed here can have an effect on these functions:
1-2: Inhibitions, reaction time, alertness
3-4: Fine motor skills, reaction time, judgment
5-7: Vision, reaction time, judgment
8-10: Speech, vision, motor skills, balance
10+: Consciousness, breathing

Long-term heavy drinking can reduce the size of brain cells, cause the brain to shrink in mass, and affect sleep, mood, emotions, and other cognitive functions.

Heavy drinking and binge drinking are associated with depression, anxiety, dementia, and suicide.

Alcohol’s Effects on the Heart

Heavy drinking or binge drinking can cause a number of cardiovascular issues:

  1. Changes in the shape of the heart muscle
  2. Irregular heartbeat
  3. Elevated blood pressure
  4. Stroke

The American Heart Association says that drinking too much alcohol can raise the level of triglycerides, contribute to obesity, increase the risk of developing diabetes, and result in sudden cardiac death.

Moderate drinking, according to the National Institute of Alcohol Abuse and Alcoholism (NIAAA), may protect healthy adults from developing coronary heart disease. The incidence of heart disease in those who drink moderate amounts of alcohol is lower than in nondrinkers.

However, the AHA does not recommend that non-drinkers begin drinking to improve heart health. Overall, the health risks of drinking alcohol outweigh possible cardiovascular benefits.

Alcohol’s Effects on the Liver

The liver needs one hour to process one drink. More than one drink per hour puts it and the body’s systems under pressure. The amount of alcohol consumed, how often, and for how long determine the risk and severity of liver damage.

Three types of liver damage are possible.

  • The first and least serious is an accumulation of fat stored in liver cells. Fatty liver is present in 90 percent of people who drink too much alcohol, and can sometimes be reversed.
  • The second is inflammation, which happens in 10 to 35 percent of people who abuse alcohol.
  • The third is cirrhosis, in which a large part of the liver is permanently replaced by scar tissue. It develops in 10 to 20 percent of heavy drinkers.


Who’s at higher risk in terms of negative effects of alcohol?

  • Women
  • Pregnant women
  • Older adults
  • People younger than 21
  • Anyone planning to drive or participate in other activities
    requiring skill, coordination, or alertness

Alcohol’s Effects on the Pancreas

Drinking excessively over a period of time can cause pancreatitis, which is the medical term for inflammation of the pancreas.

Among the symptoms of an acute pancreatic attack are abdominal pain, nausea, vomiting, fever, rapid heart rate, diarrhea, and sweating. The symptoms are treatable, but the condition is not curable. Pancreatitis is a risk factor for pancreatic cancer.

Alcohol and Cancer

The National Cancer Institute says the following types of cancer have been associated with excessive drinking.

  • Mouth cancer
  • Pharynx (throat) cancer
  • Esophagus (connects the throat to the stomach) cancer
  • Larynx (voice box) cancer
  • Breast cancer

Mixing Alcohol with Medicines

The NIAAA lists more than 100 medications than can cause harm when taken with alcohol (see the organization’s web page by clicking here).

Here are some drugs on that list older adults are likely to recognize:

  • Benadryl
  • Xanax
  • Celebrex
  • Adderall
  • Coumadin
  • Cymbalta
  • Flomax
  • Tagamet
  • Zantac
  • Lipitor
  • Crestor
  • Flexiril
  • Motrin
  • Darvocet
  • Percocet
  • Lunesta

Other Problems Associated with Alcohol

The list of other problems associated with alcohol is long, wide-ranging, and includes falls, drownings, burns, ulcers, immune system dysfunction, osteoporosis, vitamin deficiencies, domestic violence, and alcoholism.

Effects of Alcohol: Take-Away Message

If you don’t drink, don’t start. If you do drink, do it in moderation and with the knowledge that you don’t have to be a heavy drinker, a binge drinker, or an alcoholic to increase your risk of emotional and physical problems.

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Jim Brown, PhD

As a former college professor of health education, Jim Brown brings a unique perspective to health and medical writing. He has authored 14 books on health, medicine, fitness, and sports. … Read More

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