Alcohol use disorder (AUD) is a medical condition defined by a pattern of drinking that causes significant problems in your life and that you find difficult to control, even when you want to. It’s not simply drinking too much on occasion. AUD is diagnosed when at least 2 of 11 specific behavioral and physical symptoms show up within the same 12-month period, and it ranges in severity from mild to severe.
How AUD Is Diagnosed
A diagnosis of AUD is based on 11 criteria that capture different ways alcohol can take hold of someone’s life. You don’t need to meet all 11. Meeting just 2 within a year qualifies as a mild form of the disorder; 4 to 5 is moderate; 6 or more is severe. The criteria fall into a few broad patterns: loss of control, physical dependence, and ongoing use despite consequences.
Loss of control shows up as drinking more than you planned, spending a large chunk of your time obtaining, using, or recovering from alcohol, or repeatedly trying and failing to cut back. Cravings, meaning a strong urge to drink that’s hard to push aside, also count. Physical dependence includes tolerance (needing noticeably more alcohol to feel the same effect) and withdrawal symptoms when you stop or reduce drinking.
The remaining criteria focus on consequences. These include failing to keep up with responsibilities at work, school, or home; giving up hobbies or social activities you used to enjoy; continuing to drink even though it’s damaging your relationships, worsening a health problem, or putting you in physically dangerous situations. A person with severe AUD may check nearly every box on this list. Someone with mild AUD might only recognize two or three of these patterns in themselves, which is part of why the condition often goes unrecognized early on.
What Happens in the Brain
Alcohol produces its calming, loosening effect by boosting inhibitory signaling in the brain while dampening excitatory signaling. In simple terms, it turns down the brain’s “go” signals and turns up its “slow down” signals. That’s why a drink or two can make you feel relaxed and less anxious.
When someone drinks heavily over months or years, the brain adapts to this chemical tilt. It recalibrates its baseline so that alcohol becomes necessary just to feel normal. Inhibitory activity drops, excitatory activity ramps up, and the brain essentially builds alcohol into its operating system. This is what drives tolerance: you need more and more alcohol to get the effect that one or two drinks used to produce. In severe cases, people end up drinking near toxic levels just to experience relaxation or stress relief.
This recalibration also explains why withdrawal can be so unpleasant and even dangerous. Once alcohol is removed, the brain is stuck in a hyper-excitable state, which can cause anxiety, tremors, seizures, and other withdrawal symptoms until it readjusts. Brain imaging studies confirm that people with AUD have measurably lower levels of inhibitory brain chemicals during withdrawal compared to people without the disorder. Alcohol also affects the brain’s reward circuitry, triggering the release of the body’s own feel-good chemicals and reinforcing the urge to keep drinking.
Risk Factors
Genetics account for roughly 50% of a person’s risk for developing AUD. That doesn’t mean there’s a single “alcoholism gene.” Instead, hundreds of small genetic variations influence how your body metabolizes alcohol, how your brain responds to it, and how prone you are to impulsive behavior. Having a close family member with AUD significantly raises your risk, though it’s far from a guarantee.
The other half of the equation is environmental. Early exposure to alcohol, childhood trauma, chronic stress, mental health conditions like depression or anxiety, and social environments where heavy drinking is normalized all increase vulnerability. These factors often interact with genetic predisposition, which is why AUD tends to cluster in families through both biology and shared environment.
Health Consequences Over Time
The long-term physical toll of AUD extends well beyond the liver, though liver damage is one of the most well-known risks. Alcohol-related liver disease progresses through a series of stages: fatty liver, inflammation, scarring (fibrosis), cirrhosis, and eventually liver cancer in some cases. The earlier stages can reverse with sustained abstinence; cirrhosis generally cannot.
Chronic heavy drinking also weakens the heart muscle, a condition called cardiomyopathy. It raises blood pressure, increases the risk of irregular heartbeat, and over time raises the likelihood of heart attack. Blood-related problems are common too, including anemia, low white blood cell counts that weaken the immune system, and low platelet levels that impair clotting.
AUD is linked to several cancers, including cancers of the mouth, throat, esophagus, liver, and colon. It increases the risk of type 2 diabetes, thyroid disease, abnormal cholesterol levels, and reproductive problems. Nerve damage in the arms and legs, known as peripheral neuropathy, is common in people with severe AUD and causes numbness or painful burning sensations. Muscle wasting, bone fractures, recurrent gout, and chronic acid reflux round out a list that touches nearly every organ system. People who drink heavily are also more susceptible to pneumonia, tuberculosis, and other respiratory infections.
Screening and Early Detection
One of the most widely used screening tools is a three-question questionnaire called the AUDIT-C. It asks about how often you drink, how many drinks you have on a typical occasion, and how often you have six or more drinks at once. Each answer is scored from 0 to 4, for a total possible score of 12. A score of 4 or higher in men, or 3 or higher in women, suggests drinking that may be hazardous or consistent with AUD. Higher scores correlate with greater risk. The questionnaire takes under a minute and is often the first step in identifying a problem before it progresses.
Treatment Options
AUD is treatable, and treatment typically combines behavioral approaches with medication. Three medications are currently approved specifically for AUD, each working through a different mechanism.
Naltrexone blocks the brain’s opioid receptors, which are responsible for the pleasurable buzz alcohol produces. By dulling that reward, it reduces both cravings and the reinforcing “high” of drinking. It’s available as a daily pill or a monthly injection for people who prefer not to take something every day.
Acamprosate helps restore the brain’s chemical balance after someone stops drinking. It targets the excitatory signaling system that becomes overactive during prolonged abstinence, easing the persistent discomfort and anxiety that drive many people to relapse. It’s taken as a tablet three times a day.
Disulfiram takes a completely different approach. It doesn’t reduce cravings at all. Instead, it interferes with how your body breaks down alcohol, so that drinking even a small amount causes nausea, flushing, and other deeply unpleasant symptoms. It works as a deterrent rather than addressing the underlying neurobiology.
Behavioral treatments range from one-on-one cognitive behavioral therapy to group-based programs. These help people identify their drinking triggers, build coping strategies, and address co-occurring mental health issues like anxiety or depression that often fuel the cycle. Many people benefit from a combination of medication and therapy, and treatment plans are typically adjusted over time as needs change. Recovery rates improve substantially when both approaches are used together rather than either one alone.