Effects of Alcohol: What Happens to Your Body and Brain When You Drink

The effects of alcohol range from immediate changes in mood and coordination to long-term impacts on brain function, organ health, and disease risk.

What You'll Discover:

• How alcohol affects your body within minutes of drinking.

• What happens in your brain when you consume alcohol.

• Short-term effects on mood, coordination, and judgment.

• Long-term effects on major organs and systems.

• How alcohol increases the risk of certain diseases.

• Whether alcohol-related damage can be reversed.

• What options exist for reducing or stopping drinking.

The effects of alcohol begin almost immediately after your first sip. Alcohol is absorbed through the stomach lining into your bloodstream and reaches your brain within about five minutes. From there, it influences nearly every system in your body, changing how you think, feel, and function.

Understanding these effects helps you make informed decisions about drinking. According to the National Institute on Alcohol Abuse and Alcoholism, alcohol affects the brain's communication pathways, the heart, liver, pancreas, and immune system. Both short-term and long-term drinking carry health consequences worth understanding.

How Alcohol Moves Through Your Body

When you drink alcohol, it follows a predictable path through your body. Unlike food, alcohol doesn't require digestion. It passes directly through the stomach lining and small intestine into your bloodstream.

From the bloodstream, alcohol travels to every organ and tissue in your body. It crosses the blood-brain barrier easily, which is why you feel the mental effects of alcohol so quickly. The liver processes most of the alcohol you consume, breaking it down at a fairly constant rate of about one standard drink per hour.

Several factors affect how quickly you feel alcohol's effects:

• Body weight - Smaller people generally feel effects faster because alcohol is distributed through less body mass.

• Food in your stomach - Eating before or while drinking slows absorption.

• Drinking speed - Consuming drinks quickly overwhelms your liver's processing capacity.

• Biological sex - Women typically have less of the enzyme that breaks down alcohol, leading to higher blood alcohol levels from the same amount.

• Tolerance - Regular drinkers may need more alcohol to feel the same effects, though this doesn't reduce the physical harm.

Your blood alcohol concentration (BAC) determines the intensity of effects. At 0.08%, the legal driving limit in most states, coordination and judgment are noticeably impaired. At higher levels, effects become progressively more severe.

Immediate Effects on the Brain

Alcohol is classified as a central nervous system depressant. This means it slows down brain activity, though the initial effects can feel stimulating.

Within the first few drinks, alcohol affects the frontal lobes of your brain. This region controls judgment, impulse control, and social behavior. As frontal lobe activity decreases, you may feel more relaxed, talkative, and confident. Inhibitions decrease, which is why people often say things or do things while drinking that they wouldn't do sober.

Alcohol also triggers the release of dopamine in the brain's reward center. Dopamine creates feelings of pleasure and reinforces the desire to continue drinking. This reward response is part of what makes alcohol potentially habit-forming.

As BAC increases, effects spread to other brain regions:

• The cerebellum controls coordination and balance. Alcohol impairment here causes the unsteady gait and clumsy movements associated with intoxication.

• The hippocampus is responsible for forming new memories. Alcohol can block the transfer of short-term memories to long-term storage, causing blackouts where you can't remember events that occurred while drinking.

• The brainstem controls basic functions like breathing and heart rate. At very high BAC levels, alcohol can suppress these vital functions, which is why alcohol overdose can be fatal.

Research from Northwestern Medicine shows that even moderate drinking affects brain function. The effects are temporary for occasional drinkers but can become persistent with regular heavy drinking.

Short-Term Effects on Your Body

Beyond the brain, alcohol produces immediate effects throughout your body.

Cardiovascular system - Alcohol causes blood vessels to dilate, which can make you feel warm and cause flushing. Heart rate typically increases. In some people, even moderate drinking can trigger irregular heart rhythms.

Digestive system - Alcohol irritates the stomach lining, which can cause nausea and vomiting. It increases stomach acid production and can trigger acid reflux. Alcohol also affects the muscles that control digestion, which can lead to diarrhea.

Urinary system - Alcohol is a diuretic, meaning it increases urine production. This is why you need to use the bathroom more frequently when drinking. The increased fluid loss contributes to dehydration and is part of what causes hangover symptoms.

Sleep - While alcohol may help you fall asleep faster, it disrupts sleep quality. Alcohol suppresses REM sleep, which is essential for feeling rested. This is why you might sleep for eight hours after drinking and still wake up feeling tired.

Immune function - Even a single episode of heavy drinking can temporarily suppress immune function. This makes you more susceptible to infections in the hours and days following heavy drinking.

Long-Term Effects on the Brain

Chronic heavy drinking produces lasting changes in brain structure and function. Some of these changes may be reversible with sustained abstinence, while others can be permanent.

Structural changes - Research shows that heavy drinking is associated with shrinkage in certain brain regions. A study from the University of Oxford found that people who drank four or more drinks daily had nearly six times the risk of hippocampal shrinkage compared to non-drinkers. Even moderate drinkers showed more shrinkage than abstainers.

Cognitive impairment - Long-term heavy drinking can impair memory, attention, problem-solving, and decision-making. These effects may persist even during periods of sobriety, though many improve with extended abstinence.

Mental health effects - Alcohol can worsen anxiety and depression over time. While people often drink to relieve these feelings, chronic alcohol use disrupts the brain chemistry that regulates mood, often making mental health worse in the long run.

Wernicke-Korsakoff syndrome - This is a serious neurological condition caused by thiamine (vitamin B1) deficiency, which is common in heavy drinkers. Symptoms include confusion, memory problems, and difficulty with coordination. Without treatment, it can cause permanent brain damage.

For more detail on how alcohol affects brain function, our article on effects of alcohol on the brain covers the neurological impacts in depth.

Long-Term Effects on Major Organs

Chronic alcohol use affects virtually every organ system. The severity of damage depends on how much and how long you've been drinking.

Liver - The liver bears the heaviest burden because it processes most of the alcohol you consume. Chronic drinking can cause:

• Fatty liver disease, where fat accumulates in liver cells

• Alcoholic hepatitis, an inflammation of the liver

• Cirrhosis, where scar tissue replaces healthy liver tissue

Early-stage liver damage is often reversible if drinking stops. Cirrhosis is permanent, though stopping drinking can prevent further progression.

Heart - Long-term heavy drinking increases the risk of:

• High blood pressure

• Cardiomyopathy, a weakening of the heart muscle

• Arrhythmias, or irregular heartbeats

• Stroke

Pancreas - Alcohol can cause pancreatitis, a painful inflammation of the pancreas. Chronic pancreatitis can lead to digestive problems and diabetes.

Immune system - Regular heavy drinking weakens the immune system over time. This makes you more susceptible to infections including pneumonia and tuberculosis. It also slows wound healing and recovery from illness.

Digestive tract - Chronic alcohol use is associated with gastritis, ulcers, and malabsorption of nutrients. It can also contribute to malnutrition because alcohol provides calories without nutrients and can reduce appetite for healthy foods.

Alcohol and Cancer Risk

One of the most significant long-term effects of alcohol is increased cancer risk. According to the National Cancer Institute, alcoholic beverages are classified as a known human carcinogen.

Regular alcohol consumption increases the risk of several types of cancer:

• Head and neck cancers - Mouth, throat, and voice box cancers are significantly more common in people who drink regularly.

• Esophageal cancer - Risk increases substantially with alcohol consumption.

• Liver cancer - Chronic alcohol use is a leading cause of liver cancer, often developing from cirrhosis.

• Breast cancer - Even moderate drinking increases breast cancer risk. Research shows that each drink per day increases risk by about 7 to 10 percent.

• Colorectal cancer - Heavy drinking is associated with increased risk of colon and rectal cancers.

The risk increases with the amount consumed. There is no "safe" level of alcohol consumption when it comes to cancer risk, though the risk from light drinking is relatively small compared to heavy drinking.

Can Alcohol Damage Be Reversed?

One of the most common questions about alcohol's effects is whether the damage can be undone. The answer depends on what type of damage and how far it has progressed.

Brain function - Many cognitive effects of chronic drinking improve with sustained abstinence. Research suggests that within a year of stopping drinking, most cognitive damage can be reversed or improved. However, some effects may be permanent, particularly from severe or prolonged alcohol use.

Liver damage - Fatty liver disease and early-stage alcoholic hepatitis can reverse completely if drinking stops. Cirrhosis cannot be reversed, but stopping drinking prevents further damage and allows the remaining healthy liver tissue to function better.

Cardiovascular health - Blood pressure often improves within weeks of reducing or stopping alcohol. Heart function can improve over time, though some damage from cardiomyopathy may be permanent.

Cancer risk - Stopping drinking gradually reduces cancer risk over time, though former drinkers may have elevated risk compared to never-drinkers for many years.

The body has remarkable capacity for healing when given the chance. The sooner you address problematic drinking, the more reversible the damage tends to be.

Recognizing When Drinking Is Causing Problems

Understanding the effects of alcohol is useful, but applying that knowledge to your own situation matters more. Some questions to consider:

• Are you drinking more than you used to, or more than you intend to?

• Do you feel worse physically or mentally than you did before you started drinking regularly?

• Has anyone expressed concern about your drinking?

• Have you tried to cut back but found it difficult?

If you answered yes to any of these questions, your drinking may be affecting your health in ways worth addressing. Our article on understanding alcohol use disorder can help you evaluate where you stand.

Options for Reducing Alcohol's Effects

If you're concerned about the effects of alcohol on your health, you have several options.

Cutting back - For people without severe dependence, reducing consumption can significantly lower health risks. Setting specific limits, tracking drinks, and identifying triggers can help.

Taking breaks - Periods of abstinence give your body time to recover. Even a month without drinking can produce measurable improvements in liver function, sleep quality, and blood pressure.

Medication-assisted treatment - Naltrexone is an FDA-approved medication that reduces alcohol cravings and the rewarding effects of drinking. It's taken as a daily 50mg tablet and can make it significantly easier to cut back or stop.

Naltrexone works by blocking opioid receptors in the brain. When these receptors are blocked, drinking doesn't produce the same pleasurable feelings, which naturally reduces the desire to drink. Our article on how naltrexone helps stop alcohol cravings explains the mechanism in more detail.

Professional support - Working with a healthcare provider, therapist, or coach can provide structure and accountability for making changes.

Taking the Next Step

The effects of alcohol on your body and brain are real, but they don't have to be permanent. Understanding how alcohol affects you is the first step toward making informed decisions about your drinking.

If you're concerned about your alcohol use or want to reduce the health risks associated with drinking, help is available. Many people find that medication combined with support makes behavior change much more achievable.

Take the online Alcohol Use Assessment to learn more about your drinking patterns and explore whether naltrexone could help you meet your goals.