ConditionMental health & sleep
Withdrawal Syndrome
Withdrawal syndrome is the group of physical and mental symptoms that occur when someone stops or sharply reduces a substance their body has adapted to, such as alcohol, opioids, benzodiazepines, nicotine, caffeine or some antidepressants. Symptoms are often the opposite of the substance's effects: anxiety, shaking, sweating, sleeplessness, nausea and cravings. Most withdrawal is uncomfortable but not dangerous, but withdrawal from alcohol and sedatives can cause seizures and delirium and should be medically supervised. Treatment eases symptoms and helps prevent relapse.
Also called: Withdrawal, discontinuation syndrome, abstinence syndrome, substance withdrawal, detox
At a glance
- What it is
- Symptoms after stopping or reducing a substance the body has become dependent on.
- Common substances
- Alcohol, opioids, benzodiazepines and other sedatives, nicotine, caffeine, cannabis, stimulants, some antidepressants and gabapentinoids.
- Dangerous withdrawals
- Alcohol and benzodiazepines (seizures, delirium tremens), and rarely barbiturates.
- Timing
- Starts hours to days after the last dose; acute phase lasts days to weeks.
- Treatment
- Medically supervised detox, tapering, symptom-relief medicines, and ongoing addiction treatment.
When to get help
Call 911 or go to the ER
- A seizure, or hallucinations, severe confusion, agitation, high fever or racing heart during alcohol or sedative withdrawal (possible delirium tremens)
- Severe vomiting or diarrhea with signs of dehydration, chest pain or fainting
- Thoughts of suicide: call or text 988 (US) or call 911
- Using opioids again after a period of not using and becoming very drowsy or breathing slowly (overdose risk): give naloxone and call 911
See a doctor within a day or two
- Shaking, sweating, anxiety and a racing heart within a day of stopping heavy drinking
- Wanting to stop long-term benzodiazepines, sleeping pills or heavy alcohol use (do not stop suddenly; get medical advice)
- Severe opioid withdrawal symptoms: support with medicines like buprenorphine is available
Book a routine appointment
- Dizziness, "brain zaps," irritability or flu-like symptoms after stopping an antidepressant
- Headaches and tiredness after cutting caffeine
- Lingering mood or sleep problems weeks after quitting a substance
Why withdrawal happens
With regular use, the brain and body adapt to a substance. Systems that the substance suppresses become more active to compensate, and systems it stimulates become less active. When the substance is suddenly removed, these adaptations are unopposed, causing withdrawal. This is called physical dependence. It can occur even with prescribed medicines taken as directed and does not by itself mean addiction.
Withdrawal by substance
| Substance | Starts | Peaks | Main symptoms | Danger level |
|---|---|---|---|---|
| Alcohol | 6 to 24 hours | 24 to 72 hours | Tremor, sweating, anxiety, nausea, fast heart rate; seizures (12 to 48 hours); delirium tremens (48 to 96 hours) | Can be life-threatening |
| Benzodiazepines | 1 to 2 days (short-acting) or up to a week (long-acting) | Days to weeks | Anxiety, insomnia, tremor, sensory sensitivity; seizures | Can be life-threatening |
| Opioids | 8 to 24 hours (short-acting); 2 to 4 days (methadone) | 1 to 3 days | Cravings, yawning, runny nose, sweating, goosebumps, muscle aches, diarrhea, vomiting, dilated pupils | Rarely fatal, but overdose risk after |
| Nicotine | Hours | 1 to 3 days | Cravings, irritability, poor concentration, hunger | Not dangerous |
| Caffeine | 12 to 24 hours | 1 to 2 days | Headache, fatigue, low mood | Not dangerous |
| Cannabis | 1 to 2 days | 2 to 6 days | Irritability, sleep problems, reduced appetite, anxiety | Not dangerous |
| Stimulants | Hours to days | Days | Exhaustion, sleepiness, depression, increased appetite, cravings | Risk of severe depression |
| Antidepressants (SSRIs, SNRIs) | 2 to 4 days | First week | Dizziness, "brain zaps," flu-like feelings, irritability, vivid dreams | Not usually dangerous |
Alcohol withdrawal
Alcohol withdrawal ranges from mild shakiness to delirium tremens, a medical emergency with confusion, hallucinations, fever and a fast heart rate. Risk is higher with long, heavy drinking, previous withdrawal seizures or delirium tremens, and older age. Never stop heavy drinking suddenly without medical advice.
Benzodiazepine and sedative withdrawal
Benzodiazepine withdrawal can cause anxiety, insomnia, muscle stiffness, perceptual changes and seizures. Long-term users should taper gradually over weeks to months under medical supervision. The FDA requires a boxed warning about dependence and withdrawal.
Opioid withdrawal
Very uncomfortable but rarely fatal in healthy adults. However, tolerance drops quickly, so returning to previous doses can cause a fatal overdose. Medicines for opioid use disorder, such as buprenorphine and methadone, greatly ease withdrawal and reduce overdose deaths.
Antidepressant discontinuation
Stopping SSRIs and SNRIs suddenly can cause dizziness, electric-shock sensations, nausea, irritability and sleep disturbances, especially with paroxetine and venlafaxine. Tapering slowly with your doctor reduces symptoms.
Post-acute withdrawal
Some people have lingering symptoms for weeks to months: low mood, anxiety, poor sleep, cravings and difficulty concentrating. See post-acute withdrawal syndrome.
Diagnosis and assessment
A clinician assesses the substance, amount, duration, last use, past withdrawal experiences, other medical and mental health conditions, and other substances used. Standardized scales such as the CIWA-Ar (alcohol) and COWS (opioids) measure severity and guide treatment.
Treatment
Medically supervised withdrawal (detox)
- Alcohol: benzodiazepines or other medicines to prevent seizures and delirium, plus thiamine (vitamin B1) to prevent brain damage, fluids and nutrition. Mild cases can sometimes be managed as an outpatient; severe cases need hospital care.
- Benzodiazepines: gradual taper, often switching to a long-acting benzodiazepine.
- Opioids: buprenorphine or methadone; clonidine or lofexidine and other medicines for symptoms.
- Nicotine: nicotine replacement, varenicline or bupropion.
- Antidepressants: slow tapering; sometimes restarting and tapering more gradually.
After withdrawal
Withdrawal management alone does not treat addiction. Continuing care with counseling, medicines for alcohol or opioid use disorder, and peer support reduces relapse. See substance use disorder.
Self-care for mild withdrawal
- stay hydrated and eat regular, simple meals
- rest and keep a regular sleep routine
- avoid other substances
- have a support person with you
- for caffeine, cut down gradually
Frequently asked questions
What are common withdrawal symptoms?
Common symptoms include anxiety, irritability, shaking, sweating, sleep problems, nausea, headaches, muscle aches and cravings. Specific symptoms depend on the substance. Withdrawal from alcohol and sedatives can also cause seizures and delirium.
How long does withdrawal last?
Acute withdrawal usually lasts from a few days to 2 weeks, depending on the substance. Alcohol withdrawal peaks in 1 to 3 days, opioid withdrawal in 1 to 3 days, and benzodiazepine withdrawal can last weeks. Some symptoms can linger for months.
Which withdrawals are dangerous?
Alcohol and benzodiazepine (and other sedative) withdrawal can be life-threatening because of seizures and delirium tremens, so they should be medically supervised. Opioid withdrawal is rarely fatal but greatly increases overdose risk if use restarts.
Can you die from alcohol withdrawal?
Yes, in severe cases. Delirium tremens and withdrawal seizures can be fatal without treatment. Anyone who drinks heavily every day should seek medical advice before stopping. With proper treatment, withdrawal can be managed safely.
What is antidepressant discontinuation syndrome?
It is a set of symptoms, such as dizziness, electric-shock sensations, flu-like feelings, irritability and vivid dreams, that can occur when antidepressants are stopped suddenly. Tapering the dose gradually with your doctor reduces or prevents symptoms.
Sources
This guide was written from current patient and clinical guidance, including:
- American Society of Addiction Medicine (ASAM): Clinical practice guideline on alcohol withdrawal management (2020)
- SAMHSA: Medications for opioid use disorder (TIP 63)
- FDA: Boxed warning on benzodiazepine dependence and withdrawal reactions (2020)
- NICE: Depression in adults, stopping antidepressants
- National Institute on Drug Abuse (NIDA): Treatment approaches for drug addiction