Alcohol is the most socially normalized drug in the United States and one of the few whose withdrawal can kill. That combination is why alcohol use disorder often goes unaddressed for years: the drinking looks acceptable right up to the point where stopping without medical help becomes genuinely dangerous.
Quick reference
| Drug class | Central nervous system depressant. Enhances GABA, suppresses glutamate |
|---|---|
| Clinical diagnosis | Alcohol use disorder, graded mild (2 to 3 criteria), moderate (4 to 5) or severe (6 or more) |
| Is withdrawal dangerous? | Yes, potentially fatal. Seizure risk peaks at 24 to 48 hours; delirium tremens at 48 to 96 hours |
| Standard drink | 14 grams of pure alcohol: 12 oz beer, 5 oz wine, or 1.5 oz of 80 proof spirits |
| Binge drinking | 5 or more drinks for men, 4 or more for women, within about two hours |
| Heavy drinking | More than 4 drinks a day or 14 a week for men; more than 3 a day or 7 a week for women |
| FDA approved medications | Naltrexone (oral and monthly injection), acamprosate, disulfiram |
| Cancer risk | Classified as a Group 1 human carcinogen by the International Agency for Research on Cancer |
What alcohol does in the brain
Alcohol acts on two systems at once. It boosts GABA, the main inhibitory neurotransmitter, and suppresses glutamate, the main excitatory one. The result is a nervous system with the brakes applied and the accelerator disconnected.
Sustained heavy drinking forces the brain to compensate: GABA receptors become less sensitive and glutamate activity increases. That adaptation is physical dependence, and it explains exactly why withdrawal is dangerous. Remove the alcohol and what remains is a brain with too little inhibition and too much excitation, a hyperexcitable state that can escalate to seizures.
The eleven diagnostic criteria in plain terms
- Drinking more, or for longer, than you intended, repeatedly
- Wanting to cut down and not managing it
- Craving that crowds out other thoughts
- Time lost to drinking, being drunk, or recovering
- Failing responsibilities at work, school or home
- Continuing despite conflict it causes with people close to you
- Giving up activities that used to matter
- Drinking in situations that put you at risk, such as driving
- Continuing despite a physical or psychological problem it clearly worsens
- Tolerance, needing more for the same effect
- Withdrawal symptoms, or drinking to head them off
Two patterns get rationalized hardest and both indicate physical dependence: drinking in the morning, and drinking to stop feeling sick.
Withdrawal timeline
- 6 to 12 hours: tremor, sweating, anxiety, nausea, headache, insomnia, raised pulse and blood pressure.
- 12 to 24 hours: in some people, hallucinations while otherwise alert and oriented.
- 24 to 48 hours: peak seizure risk. Seizures can occur without warning.
- 48 to 96 hours: delirium tremens in a minority. Confusion, severe agitation, fever, dangerous cardiovascular instability. Untreated mortality is significant; with hospital treatment it drops sharply.
- Weeks to months: unstable sleep, mood and concentration. This is when most relapses occur, not the first week.
Higher risk applies if you have withdrawn before, have had a withdrawal seizure, drink daily in large amounts, are older, or have significant medical problems. If you are physically dependent on alcohol, get a medical assessment before you stop.
Long term health effects
- Liver: fatty liver, alcoholic hepatitis, fibrosis, cirrhosis. Early stages are substantially reversible with abstinence.
- Cancer: strongest links to cancers of the mouth, throat, esophagus, larynx, liver, colon and rectum, and female breast. Risk is dose dependent and begins below what most people consider heavy drinking.
- Heart: high blood pressure, atrial fibrillation, cardiomyopathy, raised stroke risk.
- Brain: memory and executive function decline. Thiamine deficiency can cause Wernicke encephalopathy and, untreated, the largely permanent memory damage of Korsakoff syndrome.
- Pancreas and gut: acute and chronic pancreatitis, gastritis, bleeding.
- Sleep: alcohol shortens the time to fall asleep, then fragments the second half of the night and suppresses REM.
Treatment
Three medications are FDA approved and all are badly underused. Naltrexone blocks the opioid receptors involved in alcohol reward, reducing heavy drinking days and craving, and is available as a daily tablet or monthly injection. Acamprosate helps stabilize the glutamate and GABA imbalance left after long term drinking. Disulfiram causes an unpleasant reaction to alcohol and works for motivated patients with supervision.
On the therapy side, cognitive behavioral therapy, motivational interviewing and family or couples work all have solid evidence, with couples work carrying some of the strongest outcome data in the field. Mutual help groups including Alcoholics Anonymous, SMART Recovery, LifeRing and Refuge Recovery are free and worth trying; fit matters more than brand.
Common questions
Is it safe to quit drinking cold turkey?
Not necessarily. If you drink daily or heavily and have ever had shakes, sweats or nausea on stopping, unsupervised withdrawal carries a risk of seizures and delirium tremens. Get a medical assessment first. For light or occasional drinkers, stopping abruptly is generally safe.
Can liver damage from alcohol be reversed?
Fatty liver often resolves within weeks to months of abstinence, and alcoholic hepatitis can improve considerably. Established cirrhosis involves permanent scarring, but stopping still improves survival and slows progression.
How long until I feel normal after quitting?
Acute withdrawal usually resolves within about a week. Sleep, mood, anxiety and concentration often stay unsettled for weeks to a few months. Knowing this in advance matters, because month two is when many people relapse believing recovery has failed.
Do I have to aim for total abstinence?
Abstinence is the safest target and is necessary if you have liver disease, are pregnant, or have had a withdrawal seizure. For some people a documented reduction in heavy drinking days is a legitimate and clinically meaningful starting point.
Sources
- National Institute on Alcohol Abuse and Alcoholism, drinking levels and alcohol use disorder
- DSM-5-TR, alcohol use disorder criteria
- American Society of Addiction Medicine, clinical practice guideline on alcohol withdrawal management
- International Agency for Research on Cancer, classification of alcohol as a Group 1 carcinogen
Need help now? In an emergency call 911. If you are in crisis or thinking about suicide, call or text 988 (Suicide and Crisis Lifeline; veterans press 1). For free, confidential treatment referrals 24 hours a day, call the SAMHSA National Helpline at 1-800-662-4357. You can also search licensed programs at FindTreatment.gov, or use our rehab directory and state listings.
Addiction Now publishes health journalism and reference material. This page is not medical advice, a diagnosis, or a treatment plan. Do not stop a prescribed medication without talking to a clinician. Withdrawal from alcohol, benzodiazepines and barbiturates can cause seizures and can be fatal without medical supervision.
Related reference pages
Reviewed and updated July 30, 2026 by the Addiction Now editorial team. Figures cited come from the CDC, NIDA, SAMHSA and the FDA.
