Alcohol withdrawal produces a range of symptoms that can start as early as six hours after your last drink, from mild anxiety and shaking to life-threatening seizures and delirium. The specific symptoms you experience, and how dangerous they become, depend on how long and how heavily you’ve been drinking, whether you’ve gone through withdrawal before, and your overall health.
Early Symptoms: The First 6 to 24 Hours
The earliest withdrawal symptoms tend to appear within six to 12 hours after your last drink. These are usually the mildest and include headache, anxiety, insomnia, nausea, and sweating. You may feel restless or irritable, and your hands might start to tremble. Many people describe it as a severe hangover that doesn’t improve the way a normal hangover would.
Tremors, often called “the shakes,” typically begin within five to 10 hours and get worse over the next day or two, peaking somewhere around 24 to 48 hours. Your heart rate and blood pressure often rise during this period as your nervous system shifts into overdrive. Sweating, especially in sudden waves, is common even at this early stage.
Why Your Brain Reacts This Way
Alcohol enhances the activity of your brain’s main calming chemical (GABA) while suppressing its main excitatory chemical (glutamate). Drink heavily and often enough, and your brain adapts to this constant sedation by dialing down its own calming signals and ramping up excitatory ones to compensate. When you suddenly stop drinking, that compensation doesn’t reverse immediately. You’re left with too little calming activity and too much excitatory activity, which is why withdrawal feels like your nervous system is firing on all cylinders: racing heart, trembling, sweating, anxiety, and in severe cases, seizures.
Research measuring these brain chemicals in people going through acute withdrawal confirms this directly. GABA levels drop significantly below normal while glutamate levels spike, creating a ratio that’s dramatically tilted toward overexcitation.
Moderate to Severe Symptoms: 24 to 72 Hours
For most people with mild to moderate withdrawal, symptoms peak between 24 and 72 hours after the last drink and then begin to ease. But for some, this window is when the most dangerous complications emerge.
Hallucinations can begin within 12 to 24 hours and last up to two days. These are typically visual (seeing things that aren’t there) but can also be auditory or tactile, like feeling insects crawling on your skin. Unlike the confusion of delirium tremens, people experiencing alcohol hallucinosis often know the hallucinations aren’t real.
Seizures are one of the most serious withdrawal complications. They can occur anywhere from six to 48 hours after the last drink, with the highest risk at around 24 hours. These are generalized seizures, meaning they affect the whole brain and cause full-body convulsions. It’s common for multiple seizures to occur over several hours.
Delirium Tremens
Delirium tremens, or DTs, is the most severe form of alcohol withdrawal. It usually begins two to three days after the last drink but can be delayed by more than a week. Peak intensity hits around four to five days in. Only about 5% of people going through alcohol withdrawal develop DTs, and the lifetime risk for people with chronic alcohol addiction is estimated at 5 to 10%.
DTs involve severe confusion, disorientation, hallucinations, agitation, fever, and dangerous spikes in heart rate and blood pressure. Unlike milder withdrawal, a person in delirium tremens typically cannot recognize where they are or what’s happening. This is a medical emergency that requires hospital care.
What Makes Withdrawal More Dangerous
Not everyone faces the same level of risk. Several factors push withdrawal toward the severe end of the spectrum:
- Previous withdrawal episodes. Each round of withdrawal can sensitize the brain, a phenomenon called kindling. People who’ve been through withdrawal multiple times are more likely to have seizures or DTs the next time.
- History of withdrawal seizures or delirium tremens. If you’ve had either before, your risk of experiencing them again is significantly higher.
- Heavy daily intake. Drinking more than eight drinks per day is a marker for complicated withdrawal.
- Long duration of heavy use. Years of consistent heavy drinking give the brain more time to adapt, making the rebound more intense.
- Age over 65. Older adults metabolize alcohol and medications differently, and often have other health conditions that complicate withdrawal.
- Use of sedative medications alongside alcohol. Combining alcohol with benzodiazepines or similar drugs creates deeper neurological dependence.
- High blood alcohol levels at presentation. Showing up to care with a blood alcohol level above 200 mg/dL is an independent predictor of severe withdrawal.
A scoring tool called the CIWA-Ar is widely used in medical settings to rate withdrawal severity. It evaluates 10 symptoms: nausea, tremor, sweating, anxiety, agitation, tactile disturbances, auditory disturbances, visual disturbances, headache, and orientation. Scores below 10 indicate mild withdrawal that may not require medication. Scores of 15 or above signal severe withdrawal with a risk of delirium tremens.
What Treatment Looks Like
People with mild symptoms and no history of complicated withdrawal can often be managed as outpatients, provided they have a stable living situation, a support person at home, and no serious co-occurring medical or psychiatric conditions. This usually means scheduled check-ins, medication if needed, and clear instructions on warning signs that require emergency care.
For moderate to severe withdrawal, inpatient treatment is the safer route. The World Health Organization recommends long-acting sedative medications as the frontline treatment. These medications work on the same brain receptors that alcohol affects, essentially providing a controlled, tapering version of the calming effect the brain has lost. Treatment typically lasts three to seven days after the last drink, with doses adjusted based on how severe symptoms are. All patients going through withdrawal should also receive thiamine (vitamin B1) to prevent a potentially permanent brain condition caused by the nutritional deficiencies that heavy drinking creates.
If a seizure occurs during withdrawal, the same class of sedative medications is used to prevent additional seizures. Antipsychotic medications and seizure-specific drugs are not recommended as standalone treatments.
How Long Symptoms Last
Acute withdrawal symptoms typically improve within five days for most people. By the end of a week, tremors, nausea, and the worst of the anxiety have usually subsided. But a small number of people experience what’s called post-acute withdrawal syndrome, or PAWS, where certain symptoms linger for weeks, months, or in some cases longer.
The most common lingering symptoms are insomnia, mood swings, irritability, depression, anxiety, difficulty concentrating, and cravings for alcohol. These reflect the time it takes for your brain’s chemical balance to fully recalibrate after prolonged heavy drinking. PAWS is still not well defined in medical literature, and there’s no consensus on formal diagnostic criteria, but the experience is real and widely reported by people in recovery. Knowing that these symptoms are a normal part of the brain healing, not a sign of failure, can make the weeks after acute withdrawal less alarming.