Know the Facts

Helping you make informed decisions about your drinking


What causes withdrawal?

Alcohol withdrawal is a physical reaction to cutting down or stopping alcohol use. It is most common in people who are heavy drinkers because they have developed a tolerance to alcohol.

Alcohol acts in the central nervous system by changing the balance of neurotransmitters, which are chemicals that send messages between nerves. Alcohol reduces the effect of excitatory neurotransmitters, and increases the effect of inhibitory neurotransmitters, altering the natural balance of the nervous system.

Over time, the brain tries to fix this imbalance by increasing the activity of the excitatory neurotransmitters and decreasing the activity of the inhibitory neurotransmitters. When alcohol is suddenly taken away, this compensatory effect keeps going, resulting in overactivity of the excitatory neurotransmitters and underactivity of the inhibitory neurotransmitters. This causes withdrawal syndrome.

(Normal Balance between inhibitory and excitatory transmitters)(Alcohol increases inhibitory transmitters)(Brain restores balance by increasing excitatory transmitters)(Excitatory transmitters stay elevated when alcohol is removed)

What are the symptoms?

Withdrawal symptoms depend on the amount you were drinking and for how long. Some people will have only mild symptoms while others will have severe, even life-threatening symptoms.

Mild to moderate symptoms

These can start 6-48 hours after people stop drinking or cut down, and usually last 1-5 days. They include:

  • Shaking
  • Sweating
  • Racing heart
  • Feeling sick and vomiting
  • Headaches
  • Trouble sleeping
  • Feeling anxious or agitated
  • Hallucinations

Very severe symptoms

  • Seizures
    • Usually occur within the first two days
    • Occur in about 2-9% of alcohol dependent people
  • ‘Delirium tremens’
    • Usually occur 3-4 days after stopping drinking and typically resolves within 3 days
    • Occur in about 5% of people admitted to hospital for alcohol problems
    • Includes:
      • Vivid hallucinations
      • Confusion and disorientation
      • Agitation and hyperactivity
      • Insomnia
      • Trembling
      • Racing heart
      • Sweating and fever

What do I do?

Withdrawal can be very serious, even fatal. It is important to always check in with a doctor BEFORE you stop or cut back your drinking, as it is hard to know how your body will react and how severe your withdrawal will be. Even if you don’t drink every day, you can still experience withdrawal when you stop. Your doctor will be able to assess your withdrawal risk and may prescribe you some short-term medication if needed. They may even suggest that you go to a detox centre to get help cutting down safely.


  • Haber, P., Lintzeris, N., Proude, E., & Lopatko, O. (1999). Guidelines for the Treatment of Alcohol Problems – Chapter 5: Alcohol withdrawal management. Department of Health and Ageing, Australian Government. ISBN: 1-74186-976-5
  • Knight, R.G. (2001). Neurological consequences of alcohol use. In N. Heather, T.J. Peters & T. Stockwell (Eds.). International Handbook of Alcohol Dependence and Problems. (pp. 103-127). West Sussex: John Wiley & Sons Ltd.
  • Saitz, R. (1998). Introduction to alcohol withdrawal. Alcohol Health and Research World, 22, 5-12.
  • Valenzuela, C.F. (1997). Alcohol and neurotransmitter interactions. Alcohol Health and Research World, 21, 144-148.