Alcohol is the most widely consumed addictive substance in America, the National Council on Alcoholism and Drug Dependence (NCADD) publishes. The National Institute on Alcoholism and Alcohol Abuse (NIAAA) reports that close to 90 percent of American adults cite alcohol use at some time in their lives, and nearly three-quarters of the adult population consumed alcohol in 2014.

What Are the Physical Effects of Alcohol Abuse?

How Alcohol Works in the Body and Brain

Alcohol is a socially acceptable and easy accessible mind-altering substance. When someone drinks alcohol, changes are made to brain chemistry. For example, alcohol increases the presence of gamma-aminobutyric acid, or GABA, in the brain. GABA reduces anxiety and slows down functions of the central nervous system like heart rate and blood pressure, while lowering the temperature of the body. GABA is one of the brain’s chemical messengers that acts like a natural tranquilizer, helping to minimize the stress response. Elevated levels of GABA induce relaxation, sedation, drowsiness, and mellow feelings. Another neurotransmitter impacted by drinking alcohol is dopamine, which helps the brain to control emotions and impulses as well as manage memory and sleep functions. High levels of dopamine make a person feel happy, thereby increasing the desire to drink.

Binge drinking is a pattern of alcohol consumption that raises a person’s blood alcohol concentration (or BAC) to 0.08 g/dL or above, and it usually occurs when a man drinks five drinks in a sitting (a period of around two hours) or a women drinks four drinks, NIAAA publishes. The Centers for Disease Control and Prevention (CDC) cites binge drinking as the most typical form of excessive drinking in the United States, as one out of every six adults drinks binge drinks at least four times a month and commonly consumes eight drinks each time.



Heavy drinking is another form of excessive drinking, and it occurs when five or more drinks are consumed on at least five days within a month. The Substance Abuse and Mental Health Services Administration (SAMHSA) reports that nearly 6.5 percent of Americans aged 12 and older were considered heavy drinkers in 2014. Patterns of excessive drinking can cause damage to many internal organs, including the brain; heighten risk factors for various diseases; increase rates of accidents and injuries; and lead to a multitude of physical health issues and ailments.

Initial Effects of Alcohol and Stages of Intoxication

BAC is used to measure how much alcohol is in the bloodstream, and generally speaking, the higher the BAC, the more intoxicated a person will become and the more effects alcohol will have. Alcohol affects each person differently, and things like gender, body mass index, race, genetics, rate of consumption, food intake, polydrug abuse, medical and/or mental health concerns, and metabolism can all impact how significantly alcohol intoxication may be.

NIAAA publishes the following information on levels of intoxication based on a person’s BAC and the subsequent effects of alcohol:

  • BAC of 0.0-0.05 percent: mild intoxication
  • Sleepiness
  • Relaxation
  • Mild impairment of balance, coordination, speech, memory, and attention
  • BAC of 0.06-0.15 percent: moderate to significant impairment and intoxication
  • Further impairment of balance, coordination, speech, memory, and attention
  • Relaxation turns to more significant intoxication, leading to ataxia, slurred speech, blurred vision, disorientation, and lethargy
  • Impaired reflexes, divided attention abilities, and other skills necessary for safe driving
  • Impaired decision-making abilities and judgment
  • Heightened risk of injury (both to oneself and others)
  • Increased potential for aggressive behaviors
  • BAC of 0.16-0.30 percent: severe intoxication
  • Significant impairment of balance, speech, attention, coordination, and balance
  • Potential for blackouts (amnesia)
  • Dangerous impairment of judgment and decision-making skills
  • Vomiting and alcohol poisoning possible
  • Driving skills severely impaired
  • Possible loss of consciousness
  • BAC of 0.31-0.45 percent: life-threatening levels of intoxication
  • Loss of consciousness
  • Signs of significant alcohol poisoning
  • Potentially life-threatening suppression of life-sustaining bodily functions

Alcohol intoxication can lead to questionable decision-making, decreased inhibitions, and increased risky behaviors, which may result in accident or injury. More than one person dies every hour in America as the result of an alcohol-impaired driver, the CDC warns. Alcohol can exacerbate emotions and increase the potential for aggressive and violent behaviors. The World Health Organization (WHO) reports on studies showing that in the United States over half of the victims of intimate partner violence that were studied reported that the person committing the act had recently consumed alcohol.

Alcohol Poisoning and Overdose

When too much alcohol is consumed, toxic levels can build up in the bloodstream, and an overdose, often called alcohol poisoning, can occur. Alcohol poisoning results in six fatalities every day in the United States, the CDC publishes.

Alcohol Poisoning and Overdose

As a central nervous system depressant, alcohol slows down or lowers autonomic and vital life functions, such as heart and respiration rates, blood pressure, and internal body temperature. A person may struggle to remain conscious or lose consciousness, be cold and have a weak pulse, and have difficulties breathing. Clammy skin, low blood sugar, seizures, vomiting, and a decreased gag reflex are also possible side effects of alcohol poisoning. Vomiting can cause dehydration, and lack of a gag reflex can lead a person to choke on their own vomit and aspirate.

Introducing other drugs, especially others that depress the central nervous system, can increase the risks for an overdose and tragic consequences. Alcohol poisoning is physically hazardous and can lead to coma, brain damage, and death without treatment.

Long-Term Physical Effects of Alcohol Abuse

Chronic and excessive alcohol consumption increases all potential risk factors and the odds for adverse health effects. Flushing, broken capillaries in the face, and “drinker’s nose”(where the nose turns red and takes on a bulbous appearance) are among the many physical effects that can occur due to chronic alcohol use. The American Heart Association warns that dangerous alcohol consumption can lead to obesity, diabetes, and cardiovascular complications, such as high blood pressure, stroke, cardiomyopathy, cardiac arrhythmia, and sudden cardiac death. In addition it can lead to a heightened risk for suicide, accidents, and some forms of cancer. The development of head and neck cancer, esophageal cancer, breast cancer, and liver cancer have all been tied to alcohol consumption, according to information published by the National Cancer Institute.

Per the American Liver Association, drinking too much too often can damage cells in the liver and lead to three forms of liver disease: fatty liver disease, alcoholic hepatitis, and cirrhosis. Liver disease is often progressive, and while the early stages (fatty liver disease) may be reversed with abstinence, late-stage liver disease (alcoholic cirrhosis) may not be. Liver disease may be characterized by fatigue, weakness, abdominal pain, jaundice, loss of appetite, nausea, vomiting, and fever. In 2014, the CDC reports that nearly 20,000 people died from alcohol-related liver disease.

Alcohol abuse can also lead to malnutrition, dehydration, and changes in appetite levels as well as sleep issues. Weight fluctuations may be common when someone drinks excessive amounts of alcohol, as it can lead to consumption of a lot of empty calories.

Individuals who drink a lot may also make poor diet choices and nutrition may suffer. Essential vitamins may be diminished or depleted. For instance, alcohol depletes levels of vitamin B1, or thiamine, in the brain; this can be toxic and lead to Wernicke-Korsakoff syndrome. Wernicke encephalopathy can be life-threatening and cause mental confusion, lack of coordination, staggering gait, stumbling, and abnormal and involuntary eye movements. Wernicke encephalopathy caused by alcohol abuse may progress into a form of alcohol-related dementia known as Korsakoff syndrome. The Alzheimer’s Association reports that Korsakoff syndrome is a chronic memory disorder that can cause memory gaps, confabulation (when a person makes up things to fill memory gaps), difficulty learning new information, and trouble remembering recent events. Korsakoff syndrome is often irreversible, and individuals may require around-the-clock care and supervision.

Alcohol’s Effects on the Brain

Along with the risk for alcohol-related memory problems and possible onset of dementia, the brain is damaged in other ways by excessive alcohol abuse. Over time and with chronic exposure to alcohol, the brain can become tolerant to alcohol’s effects. This can often cause a person to increase the amount and frequency of their alcohol consumption. Drinking more alcohol raises the odds for adverse reactions and increased health problems, and it speeds up the rate of dependence. Disruption in brain chemistry can cause the brain to rely on the presence of alcohol to then feel “balanced,” and when alcohol is not active in the bloodstream, withdrawal symptoms and cravings may occur.

Alcohol dependence is often a precursor or component of alcohol addiction. In 2014, the National Survey on Drug Use and Health (NSDUH) reported that 17 million Americans suffered from alcohol addiction.

When someone is dependent on alcohol, they should never stop drinking “cold turkey,” as alcohol withdrawal can be fatal. Instead, medical detox can aid in the management of withdrawal and ensure the individual’s safety.

The CDC warns that alcohol contributed to over 30,000 fatalities in 2014, not counting homicides and accidents that may have been related to alcohol use and/or intoxication. Alcohol abuse can have many negative physical effects, but help is available. Addiction treatment programs can help clients to safely process alcohol out of the body and then aid in maintaining long-term abstinence through a variety of treatment methods.