Key Highlights
  • Alcohol (ethanol) is a psychoactive substance produced by fermenting sugars
  • It is the most commonly used addictive substance in the United States
  • Alcohol acts as a central nervous system depressant, slowing brain activity
  • Approximately 29.5 million Americans aged 12+ had alcohol use disorder in 2021
  • Chronic heavy drinking causes liver disease, cardiovascular damage, and neurodegeneration
  • Alcohol withdrawal can be life-threatening and requires medical supervision
  • Genetic factors account for roughly 50% of the risk for alcohol addiction
  • Treatment includes medical detox, behavioral therapy, and FDA-approved medications

Published: February 2026 | Last Updated: February 2026 | Reading Time: 6 min

What Is Alcohol?

Alcohol, scientifically known as ethanol or ethyl alcohol (C₂H₅OH), is a psychoactive substance produced through the fermentation of sugars by yeast. It is one of the oldest and most widely consumed recreational substances in human history, with evidence of fermented beverages dating back approximately 9,000 years.

Types of Alcoholic Beverages

Alcoholic beverages fall into three main categories: beer (typically 4-6% alcohol by volume), wine (12-15% ABV), and spirits or distilled liquors (40-50% ABV). The concentration of ethanol determines the strength and intoxicating potential of each beverage.

A standard drink in the United States contains approximately 14 grams of pure alcohol, equivalent to 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of distilled spirits.

How Alcohol Affects the Body and Brain

When consumed, alcohol is rapidly absorbed through the stomach lining and small intestine into the bloodstream. It crosses the blood-brain barrier within minutes, where it begins altering neurotransmitter activity.

Neurological Effects

Alcohol enhances the effects of gamma-aminobutyric acid (GABA), the brain's primary inhibitory neurotransmitter, producing feelings of relaxation and sedation. Simultaneously, it inhibits glutamate, the main excitatory neurotransmitter, further slowing neural activity. This dual action explains alcohol's depressant effects on coordination, judgment, and reaction time.

At low doses, alcohol may produce feelings of euphoria and lowered inhibitions as it stimulates dopamine release in the brain's reward circuitry. At higher doses, the depressant effects dominate, causing slurred speech, impaired motor function, memory blackouts, and in severe cases, respiratory depression.

Physical Health Effects

Short-term effects of alcohol consumption include dehydration, nausea, impaired coordination, and hangovers. Long-term heavy drinking can damage virtually every organ system in the body, particularly the liver (fatty liver, hepatitis, cirrhosis), the cardiovascular system (cardiomyopathy, arrhythmias, hypertension), the gastrointestinal tract (gastritis, pancreatitis), and the brain (Wernicke-Korsakoff syndrome, cognitive decline).

When Drinking Becomes Alcohol Use Disorder

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR) defines alcohol use disorder (AUD) as a chronic relapsing brain disease characterized by an impaired ability to stop or control alcohol use despite adverse consequences. AUD is diagnosed on a spectrum from mild (2-3 symptoms) to severe (6+ symptoms).

Risk Factors

Multiple factors contribute to the development of AUD. Genetic predisposition accounts for approximately 50% of the vulnerability, with specific genes affecting alcohol metabolism, reward sensitivity, and impulse control. Environmental factors including early exposure to alcohol, peer influence, stress, and trauma also play significant roles.

Warning Signs

Common indicators of AUD include drinking more or longer than intended, unsuccessful attempts to cut down, spending significant time obtaining, drinking, or recovering from alcohol, experiencing cravings, continuing to drink despite relationship or health problems, developing tolerance, and experiencing withdrawal symptoms when not drinking.

Alcohol Withdrawal

Alcohol withdrawal is a potentially life-threatening medical condition that occurs when someone who has been drinking heavily for an extended period suddenly stops or significantly reduces their intake. Symptoms can range from mild anxiety and tremors to severe complications including seizures and delirium tremens (DTs).

The withdrawal timeline typically begins 6-12 hours after the last drink and peaks between 24-72 hours. Medical detox provides 24/7 monitoring and pharmacological management to ensure patient safety during this critical period.

Treatment for Alcohol Addiction

Evidence-based treatment for AUD combines medical intervention with behavioral therapies. FDA-approved medications for alcohol use disorder include naltrexone (reduces cravings), acamprosate (helps restore brain chemistry), and disulfiram (creates an aversive reaction to alcohol).

Behavioral approaches such as cognitive-behavioral therapy, motivational enhancement therapy, and 12-step facilitation help individuals develop coping strategies, identify triggers, and build lasting recovery skills.

Frequently Asked Questions

What is considered heavy drinking?

The NIAAA defines heavy drinking as more than 4 drinks per day or 14 per week for men, and more than 3 drinks per day or 7 per week for women.

Can moderate drinking be safe?

Recent research increasingly suggests that no level of alcohol consumption is completely risk-free. The 2020-2025 Dietary Guidelines recommend that adults who choose to drink should limit intake to 2 drinks or fewer per day for men and 1 drink or fewer for women.

Is alcohol addiction genetic?

Genetics account for approximately 40-60% of the risk for developing AUD. However, having a genetic predisposition does not guarantee addiction — environmental and behavioral factors also play crucial roles.

How long does alcohol stay in your system?

The liver metabolizes approximately one standard drink per hour. Alcohol can be detected in breath for up to 24 hours, in urine for 12-48 hours (or up to 80 hours with advanced testing), and in hair for up to 90 days.

References

  1. National Institute on Alcohol Abuse and Alcoholism. (2023). Alcohol Use Disorder: A Comparison Between DSM–IV and DSM–5.
  2. Centers for Disease Control and Prevention. (2023). Excessive Alcohol Use.
  3. World Health Organization. (2024). Global Status Report on Alcohol and Health.
  4. Substance Abuse and Mental Health Services Administration. (2022). National Survey on Drug Use and Health.
  5. Edenberg, H.J. & Foroud, T. (2013). Genetics and alcoholism. Nature Reviews Gastroenterology & Hepatology.

This article was reviewed by the Valley Spring Recovery Center Editorial Team. For more information about alcohol addiction treatment, call (201) 781-8812 or visit our admissions page.

Valley Spring Recovery Center — Evidence-based addiction treatment in Norwood, New Jersey.