The typical course of untreated alcohol withdrawal. The red band marks the period when withdrawal seizures and delirium tremens are most likely; timings vary between people, and medical treatment changes this picture considerably.
Key takeaways
- Alcohol withdrawal typically starts 6–24 hours after the last drink, peaks at 24–72 hours, and eases for most people by days 5–7.
- Withdrawal seizures usually occur 12–48 hours after the last drink, and alcohol hallucinosis can appear in the same window.
- Delirium tremens (DTs) usually starts 48–96 hours after the last drink. It affects a minority of people in withdrawal but is a medical emergency that can be fatal without treatment.
- Risk rises with past withdrawals (“kindling”), previous seizures or DTs, heavy daily drinking, older age and other medical conditions.
- Medically supervised detox uses regular symptom scoring (such as the CIWA-Ar scale), benzodiazepines and thiamine to keep withdrawal safe.
- Sleep problems, anxiety and cravings can continue for weeks to months as post-acute withdrawal (PAWS), which is why aftercare matters.
Medical safety first: Do not stop drinking suddenly on your own if you drink heavily every day or have had withdrawal symptoms before. Alcohol withdrawal can cause seizures and delirium tremens, both of which can be life-threatening. Speak to a doctor or an addiction-medicine service first. If someone has a seizure, becomes confused or is hallucinating, call 911.
Alcohol withdrawal usually begins 6 to 24 hours after the last drink, peaks between 24 and 72 hours, and most symptoms ease within about 5 to 7 days.12 It becomes dangerous when seizures (most often 12 to 48 hours in) or delirium tremens (typically 48 to 96 hours in) develop.13 That is why anyone who drinks heavily every day should speak to a doctor before stopping, rather than quitting cold turkey at home.
Stopping or cutting back on alcohol after a period of heavy, regular drinking is a brave and important decision. It is also one of the few situations in addiction medicine where the physical process of stopping can itself be dangerous. Up to half of people with alcohol use disorder have some withdrawal symptoms when they stop drinking, and a smaller group need medical care and monitoring to get through potentially dangerous symptoms safely.4 Understanding the alcohol withdrawal timeline, and knowing which signs mean “this is uncomfortable” and which mean “this is an emergency”, helps people and their families plan a safe way forward.
This guide explains how long alcohol withdrawal lasts, the signs of alcohol withdrawal at each stage, who is at highest risk of complications, how medical detox works, and what families can do to help.
Why Does Alcohol Withdrawal Happen?
Alcohol withdrawal happens because the brain adapts to regular heavy drinking and then overreacts when alcohol is suddenly removed. Alcohol is a central nervous system depressant: it boosts the calming effect of GABA and dampens glutamate, the brain’s main excitatory signal.1
With daily drinking, the brain compensates by reducing GABA activity and increasing glutamate activity so it can function despite the alcohol. When drinking stops or drops sharply, that compensation is suddenly unopposed. The nervous system becomes overexcited, producing tremor, a racing heart, sweating, anxiety and, in more severe cases, seizures and delirium.1
This is physical dependence, and it can develop in anyone who drinks heavily over time, regardless of willpower or character. It sits at the heart of alcohol use disorder, which involves tolerance (needing more alcohol to get the same effect) and withdrawal symptoms when drinking stops.5 The brain’s stress systems also become more active during withdrawal, which helps explain why anxiety, irritability and low mood are so common, and why the pull to drink again can feel so strong.4
What Are the Signs of Alcohol Withdrawal?
The earliest signs of alcohol withdrawal are shaky hands, sweating, anxiety, nausea and trouble sleeping, usually starting within hours of the last drink.2 Symptoms can then progress, so it helps to know the full range. Clinicians group them by severity, which guides where and how withdrawal should be treated.14
Mild
- Tremor (“the shakes”), especially in the hands
- Sweating, clammy skin and feeling hot or cold
- Anxiety, restlessness and irritability
- Headache
- Insomnia and vivid dreams
- A queasy stomach and loss of appetite
- Strong cravings for alcohol
Moderate
- Obvious tremor and marked anxiety or agitation
- Nausea and vomiting
- A racing heart and raised blood pressure
- Significant sweating
- Very poor sleep and irritability
Severe — medical emergency
- Hallucinations: seeing, hearing or feeling things that are not there
- Seizures, usually generalized (whole-body) convulsions
- Confusion, disorientation or not knowing where they are
- Severe agitation, fever and drenching sweats
- A very fast heart rate or very high blood pressure
Severe symptoms can appear even after earlier symptoms seemed manageable, and a withdrawal seizure can happen without any severe warning signs beforehand. Anyone with severe symptoms needs emergency care.12
Mild vs moderate vs severe alcohol withdrawal
Clinicians describe alcohol withdrawal by severity, which guides where and how it should be treated.6
| Severity | Typical signs | What it usually means for care |
|---|---|---|
| Mild | Mild tremor, anxiety, sweating, headache, poor sleep, queasy stomach. Vital signs close to normal. | Some people with no risk factors can be managed as outpatients with a doctor’s plan and daily check-ins. Still needs medical advice first. |
| Moderate | Obvious tremor, marked anxiety and agitation, vomiting, raised heart rate and blood pressure, significant sweating. | Usually needs medication and regular symptom scoring, ideally in a supervised setting such as a medical detox program. |
| Severe | Hallucinations, seizures, confusion or disorientation, fever, very high heart rate or blood pressure (signs of possible delirium tremens). | Medical emergency. Call 911. Hospital care, often with intensive monitoring, is required. |
Withdrawal severity can change quickly, especially in the first 72 hours, which is why it is reassessed regularly during supervised detox.6
The Alcohol Withdrawal Timeline, Stage by Stage
For most people, the alcohol withdrawal timeline runs from first symptoms at 6–24 hours, to a peak at 24–72 hours, to gradual improvement over days 4–7.12 The timings below are typical ranges for unmanaged withdrawal; not everyone passes through every stage, and treatment changes the course considerably.
| Phase | Time since last drink | What to expect |
|---|---|---|
| Early withdrawal | 6–24 hours | Tremor, sweating, anxiety, nausea, headache, insomnia and a racing heart. Symptoms can begin while blood alcohol is still measurable. This is the earliest warning that the body is dependent, and the time to get medical advice rather than push through alone. |
| Alcohol hallucinosis (some people) | 12–48 hours | Mostly visual, sometimes auditory or tactile hallucinations, usually with the person otherwise aware of their surroundings. Frightening but different from DTs, and needs prompt medical assessment. |
| Withdrawal seizures | 12–48 hours (occasionally from 6 hours) | Most often within the first 48 hours, and can occur without any earlier severe symptoms. A seizure is an emergency and a sign that withdrawal may progress to DTs. |
| Peak | 24–72 hours | The peak of physical symptoms for most people: stronger tremor, sweating, vomiting, high blood pressure and heart rate, and intense anxiety. The period when monitoring and medication matter most. |
| Delirium tremens (a minority) | 48–96 hours | Confusion, disorientation, agitation, hallucinations, fever, a very fast heart rate and heavy sweating. Life-threatening without treatment and requires hospital care. |
| Subsiding | Days 5–7 | Acute symptoms ease for most people. Tiredness, poor sleep, low mood and anxiety may linger. A key window to move from detox into therapy and relapse prevention. |
| Post-acute (PAWS) | Weeks to months | Disturbed sleep, irritability, low mood, anxiety, poor concentration and cravings that come and go. A common reason for relapse; structured support makes a big difference. |
Timings are typical ranges for untreated withdrawal and vary with drinking history, past withdrawals, other substances and overall health. Medically supervised detox changes this picture significantly.13
Alcohol hallucinosis vs delirium tremens
Alcohol hallucinosis and delirium tremens both involve hallucinations, but they are different conditions. In hallucinosis, which tends to appear earlier (around 12–48 hours), the person usually knows who and where they are and has otherwise fairly stable vital signs. In delirium tremens, which usually appears later (around 48–96 hours), the person is confused and disoriented and has signs of a nervous system in overdrive: fever, a very fast heart rate, high blood pressure and drenching sweats.13 Both need medical assessment; DTs requires emergency care.
What affects your timeline
- How much and how long you have been drinking. Heavy daily drinking over a long period makes significant withdrawal more likely.1
- Past withdrawals. Repeated withdrawal episodes can make later ones start sooner, feel more intense and carry a higher risk of seizures.7
- Other substances, especially benzodiazepines, sleeping pills or opioids, which can complicate withdrawal.
- Your overall health, including age, liver disease, infection and electrolyte problems.3
- Whether withdrawal is treated. Symptom-guided medication and monitoring ease symptoms and lower the risk of seizures and DTs.6
How Long Does Alcohol Withdrawal Last?
Acute alcohol withdrawal usually lasts about 5 to 7 days, with the worst symptoms between days 1 and 3.1 Delirium tremens, when it occurs, can last several days on its own and extend the acute phase.3
After the acute phase, many people notice a longer tail of symptoms often called post-acute withdrawal syndrome (PAWS). This can include broken sleep, anxiety, low mood, irritability, poor concentration and cravings that rise and fall over weeks to months.24 PAWS is not dangerous in the way that seizures or DTs are, but it is one of the most common reasons people return to drinking, so it is worth planning for.
Sleep routines, regular meals, exercise, therapy, peer support and structured aftercare all help the brain recalibrate. Canada’s national guideline on alcohol use disorder recommends that everyone who completes withdrawal management be offered ongoing care, rather than detox being treated as the finish line.8
Who Is at Highest Risk of Dangerous Withdrawal?
The biggest predictors of severe alcohol withdrawal are a history of withdrawal seizures or delirium tremens and repeated past withdrawals.86 Other factors add to the risk:3
- Previous withdrawals (“kindling”). Each withdrawal episode can make the next one more severe, so someone who has “dried out” several times is at greater risk than a first-timer.7
- Prior seizures or DTs. A past withdrawal seizure or episode of delirium tremens is one of the strongest warning signs.
- Heavy daily drinking over a long period, especially drinking in the morning or through the night to stave off symptoms.
- Older age. Older adults are more likely to have complications and other medical conditions.
- Other medical conditions, such as liver disease, heart disease, infection, a recent head injury, or low potassium, magnesium or platelets.
- Use of other substances, particularly benzodiazepines, sleeping pills or opioids, which can complicate withdrawal. Our guide to the Xanax withdrawal timeline explains why benzodiazepine withdrawal carries its own seizure risk.
- Withdrawal symptoms that start while still drinking or with alcohol still in the blood.
If any of these apply, withdrawal should be planned with a physician and is often safest in a supervised setting. Canadian guidelines recommend that clinicians weigh factors such as past seizures or delirium tremens, alongside a structured screening tool, to decide whether withdrawal can be managed safely in the community or needs a more intensive setting.8
How Does Canada’s Guidance on Alcohol and Health Fit In?
Canada’s Guidance on Alcohol and Health (2023), published by the Canadian Centre on Substance Use and Addiction, says that less alcohol is better for health and describes risk on a continuum. It estimates that two standard drinks or fewer per week carries low risk, three to six carries moderate risk, and seven or more carries increasingly high risk, including for several cancers, heart disease and stroke.9
In Canada, a standard drink is 341 mL (12 oz) of 5% beer, cider or cooler, 142 mL (5 oz) of 12% wine, or 43 mL (1.5 oz) of 40% spirits.9 The guidance is about long-term health risk, not withdrawal thresholds. There is no exact number of drinks that guarantees withdrawal, but people who drink heavily every day, drink to avoid the shakes, or have had withdrawal symptoms before should get medical advice before cutting back.
Why Quitting Cold Turkey at Home Can Be Dangerous
Quitting alcohol cold turkey at home is dangerous for people with physical dependence because seizures and delirium tremens can develop quickly, sometimes after symptoms seemed manageable. Withdrawal can be life-threatening when someone who drinks heavily every day stops suddenly, rather than cutting back gradually or stopping with medical support.4 At home, there is no one measuring heart rate, blood pressure or temperature, no medication to prevent seizures, and no one trained to spot early delirium.
An illustration, not patient data. In supervised detox, symptoms are scored and treated as they rise; stopping alone leaves nothing in place if withdrawal escalates toward seizures or delirium tremens.
Other home-detox risks include dehydration from vomiting, falls and head injuries during tremor or seizures, low blood sugar and electrolyte problems, and Wernicke’s encephalopathy from thiamine deficiency.10 There is also a psychological risk: when symptoms become unbearable, many people drink again to make them stop, which can deepen the cycle and add to the kindling effect.7
That does not mean you should keep drinking indefinitely. The safe message is: do not stop suddenly without medical advice. A family doctor, an Ontario Rapid Access Addiction Medicine (RAAM) clinic or a residential treatment centre can assess your risk and recommend outpatient or supervised withdrawal. ConnexOntario (1-866-531-2600) offers free, confidential information about addiction services across the province.
When Does Alcohol Withdrawal Become an Emergency?
Alcohol withdrawal becomes an emergency when there is a seizure, confusion, hallucinations with fever or agitation, or any sign of delirium tremens.23 Do not wait to see whether these symptoms settle on their own.
Call 911 if…
Call 911 or go to your nearest emergency department if you or someone else has any of the following during alcohol withdrawal:
- A seizure, even a brief one
- Confusion, disorientation or not recognizing familiar people or places
- Hallucinations, especially with fever, sweating or agitation
- A very fast or irregular heartbeat, chest pain or trouble breathing
- A high fever or drenching sweats
- Repeated vomiting and being unable to keep fluids down
- New unsteadiness on the feet, eye-movement problems or sudden confusion (possible Wernicke’s encephalopathy)
- Thoughts of suicide or self-harm
In Canada, you can reach the 9-8-8 Suicide Crisis Helpline any time by call or text.
If someone has a seizure
Stay with them, move hard or sharp objects away, cushion their head and do not put anything in their mouth or try to hold them down. Time the seizure, call 911, and once the jerking stops, roll them onto their side (the recovery position) and stay until help arrives.
How Medical Detox Treats Alcohol Withdrawal
Medically supervised alcohol detox combines regular symptom scoring, medication to calm the nervous system and prevent seizures, vitamins and fluids, and round-the-clock observation. The aim is a safe, controlled withdrawal rather than a crisis.611
CIWA-Ar monitoring
Most detox services use a standardized scale called the CIWA-Ar (Clinical Institute Withdrawal Assessment for Alcohol, revised). A nurse or physician scores ten features, including nausea, tremor, sweating, anxiety, agitation, headache, sensory disturbances and orientation.12 Scores are repeated regularly, and higher scores prompt medication and closer observation. This “symptom-triggered” approach gives people the medication they need when they need it, without over-sedation.6
Benzodiazepines
Benzodiazepines such as diazepam, chlordiazepoxide or lorazepam are the first-line medications for alcohol withdrawal, with the deepest evidence base of any treatment.64 They act on the same GABA system alcohol affects, calming the overexcited brain and reducing the risk of seizures and delirium tremens.1 The dose is adjusted to symptom scores and gradually stopped over a short period, so they do not become a new dependence; Canadian guidelines advise against benzodiazepines as ongoing treatment for alcohol use disorder.8
Thiamine and nutrition
Heavy drinking often depletes thiamine (vitamin B1). Severe deficiency can cause Wernicke’s encephalopathy, a medical emergency marked by confusion, unsteadiness and abnormal eye movements, which can lead to lasting memory problems (Korsakoff syndrome).10 Detox protocols therefore give thiamine early, typically before any glucose, along with fluids, electrolytes and other vitamins as needed.1110
Other care
Detox teams also monitor blood pressure, heart rate, temperature, hydration and sleep, treat nausea, and screen for problems such as liver disease, infection and co-occurring depression or anxiety. Once withdrawal is under control, attention turns to longer-term options, which can include medications that reduce cravings and the risk of return to drinking, such as naltrexone or acamprosate, when a physician considers them appropriate.8
Detox is an essential first step, but on its own it is rarely enough: most people need further help to change their relationship with alcohol and stay well.5
How Can Families Help Someone Through Alcohol Withdrawal?
The most helpful thing families can do is encourage a medical assessment before the person stops, then stay close and watchful during the first few days. Practical steps include:
- Do not pressure a sudden stop. Pouring out all the alcohol or demanding they quit immediately can push someone into unsupervised withdrawal. Encourage a doctor’s appointment or a call to a treatment centre instead.
- Learn the warning signs. Know the emergency signs listed above and keep 911 in mind, especially 12–96 hours after the last drink.
- Do not leave them alone during the first days of withdrawal if they have stopped at home.
- Share the history. Tell clinicians about past seizures, DTs, hospital stays and other substances, since the person may be too unwell or embarrassed to do so.
- Look after yourself too. Family members often carry stress and guilt. Our family support and education program helps loved ones understand addiction, set healthy boundaries and support recovery without burning out.
Medical Detox and Treatment at Sober Living
At Sober Living Recovery & Wellness Centre, alcohol detox takes place in a residential setting with 24/7 medical supervision, followed by therapy to address why drinking became a problem in the first place.
- Confidential assessment. The intake process starts with a free, confidential consultation covering your drinking pattern, previous withdrawals, other substances, physical health and mental health. Our admissions team can also help verify coverage with private insurance or benefit plans.
- Arrival and medical review. On admission, the medical team reviews your history and vital signs and builds a withdrawal plan. Bring a list of your current medications and any recent medical records if you have them.
- Supervised withdrawal. Through our medical detox program, symptoms are monitored around the clock, medication is adjusted to your needs, and thiamine, fluids and nutrition are prioritized.
- Residential therapy. As withdrawal settles, you move into the residential alcohol addiction treatment program, with cognitive behavioural therapy (CBT), DBT, motivational interviewing, trauma-informed care, group therapy and holistic wellness. Programs typically run 30, 45, 60 or 90 days.
- Aftercare. Before you leave, the team builds a relapse-prevention and aftercare plan with alumni support and regular check-ins, so PAWS and early cravings are met with a plan rather than surprise.
If alcohol use sits alongside anxiety, depression or trauma, those are treated together as a concurrent disorder, and people who also misuse sleeping pills or other medications can be assessed through our prescription drug treatment team. Our centre is in north Etobicoke, Toronto, and our location page explains how to get here and the travel support available from across Ontario and Canada.
Worried about stopping drinking safely?
Our admissions team is available 24/7 to talk through your drinking pattern, any past withdrawals and your health, and to explain whether supervised detox is the right first step. You do not have to face withdrawal alone.
24/7 admissions · Confidential · Private insurance accepted
Frequently Asked Questions
How long does alcohol withdrawal last?
Acute alcohol withdrawal usually lasts about 5 to 7 days. Symptoms start 6 to 24 hours after the last drink, peak between 24 and 72 hours, then ease. If delirium tremens develops, it can extend the acute phase by several days. Milder symptoms such as poor sleep, anxiety and cravings can continue for weeks to months as post-acute withdrawal.
What are the first signs of alcohol withdrawal?
The first signs of alcohol withdrawal are usually shaky hands, sweating, anxiety, irritability, nausea, headache, a racing heart and trouble sleeping. They often start within 6 to 24 hours of the last drink, and sometimes while there is still alcohol in the blood. Needing a drink in the morning to stop the shakes is a strong sign of physical dependence.
When is alcohol withdrawal most dangerous?
The most dangerous period is roughly 12 to 96 hours after the last drink. Withdrawal seizures most often happen between 12 and 48 hours, and delirium tremens usually begins between 48 and 96 hours. Both are medical emergencies. Anyone who has a seizure, becomes confused or has hallucinations with fever or agitation during withdrawal needs 911.
What are delirium tremens (DTs)?
Delirium tremens is the most severe form of alcohol withdrawal. It causes confusion, disorientation, agitation, hallucinations, fever, heavy sweating and a very fast heart rate, usually starting two to four days after the last drink. It affects a minority of people in withdrawal, most often those with heavy long-term drinking or past DTs, and requires emergency hospital treatment.
Is it safe to detox from alcohol at home?
It can be for some people with mild dependence and no risk factors, but only with a doctor’s assessment and plan. For people who drink heavily every day, have had seizures or DTs, have gone through withdrawal before, are older or have other health problems, home detox is risky. Supervised medical detox is the safer choice.
What medications are used for alcohol withdrawal?
Benzodiazepines such as diazepam, chlordiazepoxide or lorazepam are the main medications, because they calm the nervous system and reduce the risk of seizures and delirium tremens. Thiamine (vitamin B1) is given to prevent Wernicke’s encephalopathy, along with fluids and electrolytes. After detox, a physician may discuss medications that reduce cravings, such as naltrexone or acamprosate.
Why is each alcohol withdrawal worse than the last?
This is called kindling. Repeated cycles of heavy drinking and withdrawal appear to make the brain more sensitive, so later withdrawals can start sooner, feel more intense and carry a higher risk of seizures. It is one reason people who have been through withdrawal several times are strongly advised to detox under medical supervision.
What is post-acute withdrawal (PAWS) after quitting alcohol?
PAWS describes symptoms that can persist after the acute withdrawal phase, such as broken sleep, anxiety, low mood, irritability, poor concentration and cravings that come in waves. It can last weeks to months and gradually improves. Therapy, regular routines, exercise, peer support and a clear aftercare plan help people get through PAWS without returning to drinking.
Sources
- StatPearls. Canver BR, Gomez AE. “Alcohol Withdrawal Syndrome.” National Library of Medicine (NIH). ncbi.nlm.nih.gov/books/NBK441882
- MedlinePlus Medical Encyclopedia. “Alcohol withdrawal.” U.S. National Library of Medicine. medlineplus.gov/ency/article/000764.htm
- StatPearls. Rahman A, Paul M. “Delirium Tremens.” (2023) National Library of Medicine (NIH). ncbi.nlm.nih.gov/books/NBK482134
- NIAAA Core Resource on Alcohol. “Alcohol Use Disorder: From Risk to Diagnosis to Recovery.” National Institute on Alcohol Abuse and Alcoholism (NIH). niaaa.nih.gov/health-professionals-communities/core-resource-on-alcohol
- Centre for Addiction and Mental Health (CAMH). “Alcohol.” CAMH, Toronto. camh.ca/en/health-info/mental-illness-and-addiction-index/alcohol
- American Society of Addiction Medicine. “The ASAM Clinical Practice Guideline on Alcohol Withdrawal Management.” (2020) ASAM. asam.org/quality-care/clinical-guidelines/alcohol-withdrawal-management-guideline
- Becker HC. “Kindling in alcohol withdrawal.” Alcohol Health & Research World. 1998;22(1):25–33. PubMed. pubmed.ncbi.nlm.nih.gov/15706729
- Canadian Research Initiative in Substance Matters (CRISM) & BC Centre on Substance Use. “Canadian Guideline for the Clinical Management of High-Risk Drinking and Alcohol Use Disorder.” (2023) CRISM. crism.ca/alcohol-use-disorder
- Canadian Centre on Substance Use and Addiction. “Canada’s Guidance on Alcohol and Health.” (2023) CCSA. ccsa.ca/en/guidance-tools-resources/substances/alcohol/canadas-guidance-alcohol-and-health
- StatPearls. Singh J, Regina AC. “Wernicke-Korsakoff Syndrome.” National Library of Medicine (NIH). ncbi.nlm.nih.gov/books/NBK470344
- World Health Organization. “Withdrawal Management” — Clinical Guidelines for Withdrawal Management and Treatment of Drug Dependence in Closed Settings. National Library of Medicine (NIH). ncbi.nlm.nih.gov/books/NBK310652
- Sullivan JT, Sykora K, Schneiderman J, Naranjo CA, Sellers EM. “Assessment of alcohol withdrawal: the revised Clinical Institute Withdrawal Assessment for Alcohol scale (CIWA-Ar).” British Journal of Addiction. 1989;84(11):1353–1357. PubMed. pubmed.ncbi.nlm.nih.gov/2597811