Alcohol abuse, also known as alcohol use disorder, is a widespread medical condition that affects millions of people around the world, disrupting lives, relationships, and health in profound ways.

Epidemiology

Alcohol use disorder represents one of the most significant public health challenges globally. According to worldwide data from 2019, approximately 2.6 million deaths were caused by alcohol consumption, with men bearing a disproportionate burden—accounting for 2 million of these deaths compared to 600,000 among women. The highest levels of alcohol-related deaths per 100,000 people are observed in the European and African regions, with rates reaching 52.9 and 52.2 deaths per 100,000 people respectively.^[5]

An estimated 400 million people worldwide, representing about 7 percent of the global population aged 15 years and older, lived with alcohol use disorders in 2019. Of this substantial number, approximately 209 million people—3.7 percent of the adult world population—lived with alcohol dependence, which represents the more severe form of the condition.^[5]

In the United States specifically, the problem is widespread. Currently, nearly 14 million Americans—one in every 13 adults—abuse alcohol or are alcoholic. Several million more adults engage in risky drinking patterns that could lead to alcohol problems, including binge drinking and heavy drinking on a regular basis. Additionally, 53 percent of men and women in the United States report that one or more of their close relatives have a drinking problem.^[4]

The impact of alcohol extends significantly to younger populations. People of younger age, specifically those between 20 and 39 years old, are disproportionately affected by alcohol consumption. In 2019, the highest proportion—13 percent—of alcohol-attributable deaths occurred within this age group.^[5] About 178,000 people die from excessive alcohol use each year in the United States alone.^[3]

The economic consequences are staggering as well. In purely economic terms, alcohol-related problems cost society approximately 185 billion dollars per year. However, in human terms—considering broken families, lost opportunities, and shattered lives—the costs cannot be calculated.^[4]

Causes

Alcohol use disorder is fundamentally a brain disorder, which is a condition affecting the structure and function of the brain. The disorder is characterized by an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences. It encompasses what some people refer to as alcohol abuse, alcohol dependence, alcohol addiction, and the colloquial term, alcoholism.^[1]

Researchers don’t know all the reasons why someone develops alcohol use disorder, but they have identified several key factors. One major contributing factor is genetics. Studies show that people with a family history of alcohol use disorder have an increased risk of developing it themselves. Genetics play a significant role, with hereditability—the passing of traits from parents to children through genes—accounting for approximately 60 percent of the risk.^[1] However, like other chronic health conditions, alcohol use disorder risk is influenced by the interplay between a person’s genes and their environment.^[1]

Mental health conditions represent another important cause. A wide range of psychiatric conditions are associated with an increased risk of alcohol use disorder. These include depression, post-traumatic stress disorder, and attention deficit hyperactivity disorder. People with a history of childhood trauma are also particularly vulnerable to developing alcohol use disorder.^[1] Having conditions like depression, post-traumatic stress disorder, or attention-deficit/hyperactivity disorder may increase your risk of developing the disorder.^[17]

The development of addiction in the brain involves powerful effects on brain chemistry. Alcohol, like other drugs, produces pleasurable feelings and blunts negative feelings. These feelings can motivate some people to drink alcohol again and again, despite possible risks to their health and well-being. Research shows that over time, drinking to cope with stress—while it may provide temporary relief from emotional discomfort—tends to enhance negative emotional states between bouts of alcohol consumption. These changes can motivate further drinking and cause an individual to become stuck in an unhealthy cycle of alcohol consumption.^[6]

As individuals continue to drink alcohol over time, progressive changes may occur in the structure and function of their brains. These changes can compromise brain function and drive the transition from controlled, occasional use to chronic misuse, which can be difficult to control. The changes can endure long after a person stops consuming alcohol, and can contribute to relapse in drinking.^[6]

Risk Factors

A person’s risk for developing alcohol use disorder depends in part on how much, how often, and how quickly they consume alcohol. Alcohol misuse—defined as drinking in a manner, situation, amount, or frequency that could cause harm to the person who drinks or to those around them—over time increases the risk of developing the disorder. Alcohol misuse includes binge drinking and heavy alcohol use.^[1]

Drinking at an early age significantly increases risk. Research shows that among people ages 26 and older, those who began drinking before age 15 were more likely to report having alcohol use disorder in the past year compared to those who waited until age 21 or later to begin drinking. Notably, the risk for females in this group is higher than that of males.^[1]

Understanding the patterns of excessive alcohol use helps identify who is at risk. Excessive alcohol use includes several dangerous drinking behaviors. Binge drinking is defined as four or more drinks for women, or five or more drinks for men during a single occasion. Heavy drinking means eight or more drinks for women, or 15 or more drinks for men during a week. Any alcohol use by people younger than 21, and any drinking during pregnancy, also constitute excessive alcohol use.^[3]

Parents’ drinking patterns may also influence the likelihood that a child will one day develop alcohol use disorder. This suggests that both genetic factors and learned behaviors within families contribute to risk.^[1]

Symptoms

When most people think about medical condition symptoms, they may focus on physical issues like pain or fever. However, alcohol use disorder symptoms primarily focus on changes in mood and behavior, though physical symptoms are also present. Understanding these symptoms is important because the disorder can range from mild to severe based on how many symptoms a person experiences.^[17]

Health care professionals diagnose alcohol use disorder when a person has two or more specific symptoms. The disorder can be mild with the presence of two to three symptoms, moderate with four to five symptoms, or severe with six or more symptoms.^[1]

One of the core symptoms is being unable to limit the amount of alcohol you drink. This goes hand in hand with wanting to cut down on how much you drink or making unsuccessful attempts to do so. Many people with the disorder recognize they should drink less but find themselves unable to follow through on these intentions.^[2]

People with alcohol use disorder often experience a strong craving or urge to drink alcohol. This craving can become overwhelming and difficult to resist. They may spend a lot of time drinking, getting alcohol, or recovering from alcohol use, which includes dealing with hangovers caused by drinking.^[2]

The disorder causes people to continue using alcohol even though their drinking affects their relationships with family, friends, and colleagues. They may fail to fulfill major obligations at work, school, or home due to repeated alcohol use. Important social, work, or recreational activities may be given up because of alcohol.^[2]

A particularly concerning symptom is drinking more than intended, or for longer than intended. What starts as having one or two drinks can quickly escalate to much more, leaving the person feeling out of control. People may repeatedly try to reduce how much they drink but repeatedly fail to meet work or family obligations because they’re drinking.^[17]

Physical symptoms become apparent in more severe cases. People may develop a high tolerance for beverages containing alcohol, meaning they need to drink greater amounts to achieve the same effect. This is the body adapting to regular alcohol exposure and needing more to feel the same impact.^[4]

Physical dependence develops when the body becomes so accustomed to alcohol that stopping causes uncomfortable symptoms. Withdrawal symptoms such as nausea, sweating, shakiness, and anxiety occur when alcohol use is stopped after a period of heavy drinking. Some people drink to avoid these withdrawal symptoms, creating a vicious cycle.^[1]

People with the disorder may use alcohol in physically hazardous situations, putting themselves and others at risk. They may continue to drink when they have a medical condition or mental disorder that gets worse when they drink, showing how the compulsion to drink can override good judgment and self-care.^[17]

Prevention

Preventing alcohol use disorder and reducing the harms associated with alcohol consumption involves multiple strategies at both the individual and societal levels. Understanding safe drinking limits and implementing practical strategies can help prevent the development of problematic alcohol use.

To keep health risks from alcohol to a low level, both men and women are advised not to regularly drink more than 14 units a week. A unit of alcohol is 8 grams or 10 milliliters of pure alcohol, which is about half a pint of lower to normal-strength lager, beer, or cider, a single small shot measure of spirits, or a small glass of wine contains about 1.5 units of alcohol.^[7]

The American Medical Association provides specific recommendations. For men, the limit is two drinks per day, with heavy drinking defined as five or more drinks in one day or 15 or more drinks in a week. Women should limit drinking to one drink a day, with heavy drinking in this population being four or more drinks a day or eight drinks a week.^[17] Understanding what constitutes a standard drink is important—in the United States, a standard drink is one that contains about 14 grams of pure alcohol, found in 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of distilled spirits or liquor.^[8]

For those who choose to drink, specific strategies can help minimize risks. If you drink as much as 14 units a week, it’s best to spread this evenly over three or more days rather than drinking it all at once. If you’re trying to reduce the amount of alcohol you drink, it’s a good idea to have several alcohol-free days each week. Taking a break and having drink-free days allows your body to recover from the effects of alcohol.^[7]

Setting clear limits before drinking is a practical prevention strategy. Before you start drinking, set a limit on how much you’re going to drink and stick to it. Setting a budget by only taking a fixed amount of money to spend on alcohol can help enforce this limit. Letting friends and family know that cutting down is important to you can provide valuable support and accountability.^[21]

Making informed choices about what to drink can also help. You can still enjoy a drink but opt for smaller sizes, such as bottled beer instead of pints, or a small glass of wine instead of a large one. Cutting down the alcohol content by swapping strong beers or wines for ones with lower strength can reduce overall alcohol consumption. Having a glass of water before you have alcohol and alternating alcoholic drinks with water or other non-alcoholic drinks helps maintain hydration and naturally limits alcohol intake.^[21]

Complete abstinence from alcohol is the safest choice for certain groups. If you’re pregnant or trying to become pregnant, the safest approach is to not drink alcohol at all to keep risks to your baby to a minimum. People under age 21 should not drink alcohol. Those taking medicines that can interact with alcohol, people with medical conditions that get worse when drinking, and individuals in recovery from alcohol use disorder should also abstain completely.^[7]

Early intervention is key to prevention. If you’re concerned about your drinking, seeing a healthcare provider as a first step allows for assessment and guidance before problems become severe. Brief counseling sessions can provide valuable information about risks associated with drinking patterns and offer strategies for change.^[7]

Pathophysiology

Understanding what happens in the body when someone develops alcohol use disorder involves examining the changes that occur in normal bodily functions at mechanical, physical, and biochemical levels. These changes explain why the disorder is considered a chronic relapsing brain disorder and why recovery can be challenging.

Alcohol is a central nervous system depressant, which means it is a drug that slows down brain activity. When someone drinks alcohol, it changes their mood, behavior, and self-control. It causes problems with memory and thinking clearly, and affects coordination and physical control. These immediate effects result from alcohol’s action on brain chemistry and neural pathways.^[8]

As individuals continue to drink alcohol over time, progressive changes occur in the structure and function of their brains. Alcohol addiction can be understood as a repeating cycle with three stages, each linked to and feeding on the others. These stages primarily involve three domains: incentive salience, negative emotional states, and executive function. The domains are reflected in three key regions of the brain: the basal ganglia, the extended amygdala, and the prefrontal cortex, respectively.^[6]

The lasting changes in the brain caused by alcohol misuse perpetuate alcohol use disorder and make individuals vulnerable to relapse. These changes can endure long after a person stops consuming alcohol. The brain essentially becomes rewired to prioritize alcohol-seeking behavior, making it extremely difficult to stop drinking through willpower alone.^[6]

Alcohol affects organs throughout the body beyond just the brain. Your liver can only process small amounts of alcohol at a time. The rest of the alcohol can harm your liver and other organs as it moves through the body. Heavy drinking can increase the risk for certain cancers, especially those of the liver, esophagus, throat, and voice box. Heavy drinking can also cause liver cirrhosis, which is scarring and hardening of liver tissue, as well as immune system problems and brain damage.^[4]

Alcohol can raise blood pressure and heart rate. Long-term heavy drinking can lead to the heart becoming enlarged, a serious condition called alcohol-induced cardiomyopathy. This condition cannot be completely reversed, but stopping drinking can stop it from getting worse.^[7]

The development of physical dependence involves specific biochemical changes. When someone drinks heavily and regularly for some time, their body becomes dependent on alcohol. The body adapts to the constant presence of alcohol by adjusting its chemistry to function normally in its presence. When alcohol is suddenly removed, the body struggles to readjust, leading to withdrawal symptoms.^[18]

Withdrawal symptoms can include hand tremors known as “the shakes,” sweating, seeing things that are not real (visual hallucinations), depression, anxiety, and difficulty sleeping. These symptoms occur because the brain and nervous system have become dependent on alcohol to maintain balance. The severity of withdrawal symptoms depends on how much and how long someone has been drinking.^[7]

Tolerance development represents another key pathophysiological change. As the body adapts to regular alcohol exposure, more alcohol is needed to achieve the same effects. This means someone who has been drinking heavily for a long time may be able to tolerate very high levels of alcohol in amounts that would dangerously affect or even kill someone who drinks less regularly.^[7]

Alcohol also disrupts normal sleep patterns, even though it may initially help someone fall asleep. It prevents deep, restorative sleep, which explains why people who drink heavily often feel tired despite sleeping. Alcohol can affect the body’s ability to fight infections, making people who drink regularly more susceptible to infectious diseases.^[7]