What is alcohol intoxication?
Alcohol intoxication, or drunkenness, is a temporary condition caused by drinking alcohol. Severe alcohol intoxication is also known as alcohol poisoning.
Although alcohol intoxication most commonly results from Ethanol contained in commercial alcoholic beverages, there are several other types of alcohol, found in a variety of sources, that can cause it. These include:
- Methanol, which smells similar to ethanol, but is used in industrial applications
- Isopropanol, also known as isopropyl alcohol, which is used in disinfectants and antiseptics
- Ethylene glycol, which is used in antifreeze
Good to know: Methanol is extremely toxic. If consumed, ten milliliters of methanol can cause blindness, and consuming thirty milliliters is potentially fatal.
In adults, alcohol intoxication usually results from consuming alcoholic beverages. However, adults and children alike may also, accidentally or deliberately, consume the following household substances that contain alcohol:
- Colognes and perfumes
- Chafing-dish and portable camp-stove fuels
- Medications, such as cough syrup
Alcohol consumed orally is absorbed into the blood via the small intestine and the stomach, and because the body can absorb alcohol faster than it can metabolise or eliminate it, blood alcohol concentrations (BAC) peak between half an hour and ninety minutes after consumption.
Alcohol is consumed primarily because some effects of mild alcohol intoxication, such as an increased sense of well-being and increased social confidence, are considered pleasant. However, negative effects, such as a fast heartbeat and nausea, can be felt as a result of having even low blood alcohol levels.
With increasing levels of blood alcohol, symptoms like dizziness, nausea, vomiting, changes in speech or a loss of control over body movements can occur. Acute alcohol intoxication is the most common alcohol-related disorder for which people are admitted to hospital.
In severe cases, alcohol intoxication may lead to conditions that can temporarily impair the pancreas or liver. This impairment may become chronic if it recurs. However, alcohol intoxication is usually treated with fluids, and many people experience no lasting health consequences from alcohol intoxication itself, particularly if it is an isolated incident rather than a regular occurence. People who have mild to moderate alcohol intoxication usually recover well, although they may suffer symptoms including headache, nausea and vomiting for 1 or 2 days. This is known as a hangover. Heavy alcohol intoxication might result in serious health effects and may lead to complications and even death.
Risks of alcohol intoxication
Alcohol intoxication is caused by an excessive intake of alcohol; it is a very common condition.
Alcohol is a central nervous system depressant. The absorption rate of alcohol and associated risk of alcohol intoxication depends not only on the quantity of alcohol, but also on the context in which it was drunk. The severity of alcohol intoxication depends on:
- How much alcohol was ingested
- The percentage of alcohol in the beverage ingested
- The period of time over which the alcohol was ingested
- How used the affected person is to drinking alcohol and how tolerant of alcohol they are
- The affected person’s body weight
- The affected person’s biological sex
- The affected person’s metabolism
- Other health problems that the affected person may have
- Medication that the affected person might be taking
- Interaction with recreational drugs the affected person might have used
Good to know: Some medications can increase the effect of alcohol, or affect the way it is metabolised.
People who do not drink alcohol often tend to get drunk more quickly and more severely than people who drink alcohol more regularly, though this is not always the case. Women and younger adults may become intoxicated more easily than men, due to the difference in body size and the ability to process alcohol.
Drinking on an empty stomach, drinking quickly, or drinking beverages that are stronger than one is used to all increase the risk of becoming intoxicated. Binge drinking is a major cause of alcohol intoxication, and is defined as:
- In men: drinking five or more units of alcohol in two hours
- in women: drinking four or more units of alcohol in two hours.
- 25 milliliters/0.8 US fl oz of whiskey
- 250 milliliters/8.4 US fl oz of standard beer
- 250 milliliters/8.4 US fl oz of alcopop
- 76 milliliters/2.5 US fl oz of wine
Good to know: Most countries recommend that adult men and women do not consume more than 14 units of alcohol a week.
Symptoms of alcohol intoxication
The symptoms depend on the level of alcohol in the blood, and whether the individual drinks alcohol regularly.
Early symptoms of alcohol intoxication include:
- A rapid heart beat
- A feeling of well-being and confidence
- Reddening of the skin
- An unsteady gait
Symptoms of worsening intoxication include:
- Reduced attentiveness
- Slurred speech
- Loss of control of body movements
- Loss of consciousness (blackouts)
People with very severe intoxication may become very cold, dehydrated and may develop seizures.
The symptoms of ethanol intoxication change, depending on how many milligrams of alcohol have been consumed.
- A feeling of tranquility and relaxation
- Impairment in tasks requiring skill and/or fine motor coordination
- Mild feelings of sedation
- Increasing trouble with fine motor coordination
- Impaired judgement
- Altered perceptions of the environment around them
- Changes in mood, behaviour and personality, and loss of inhibitions
- Memory impairments
- Slowed reaction time
- Slurred speech
- Clumsiness and unsteady gait
- Uncontrolled eye movements
- Nausea and vomiting
- Problems speaking and articulating
- Double vision
- Hypothermia, or feeling very cold
- Respiratory depression
In people who are alcohol-naive, meaning that they do not regularly consume alcohol, a level of 400mg or above may be fatal. People who habitually consume alcohol and people with alcoholism can consume relatively more alcohol and therefore have higher blood alcohol levels (BAC levels), without displaying symptoms of intoxication than can people who do not consume much alcohol. However, symptoms and risk will always be present in some form.
Good to know: Alcohol poisoning can cause sudden death due to respiratory depression and heart arrhythmia. This is particularly true if the intoxicated person is asleep, or falls asleep or unconscious.
- Smell of alcohol on breath or clothing
- Enlarged pupils
- Redness of the face
- Slow breathing
- Faster-than-usual eye movements
- Lack of alertness
- Semi-consciousness or lack of responsiveness
- Incoherent speech
Some symptoms of alcohol poisoning need immediate emergency medical attention. These include:
- Breathing problems
- Uncontrollable vomiting
- Chest pain
Good to know: Moderate or serious alcohol intoxication can cause the affected person to lose alertness or become semi-conscious and can also cause vomiting. Therefore, it is important to monitor them to minimise the risk of aspiration, or inhalation, of vomit. Aspirated vomit can cause death through suffocation, or can lead to bacterial infection of the lungs. To minimize the risk of vomit being aspirated, place the affected person in the recovery position, in which the person is placed on their side, facing slightly downwards, supported by bent limbs. A person in this condition must be monitored, and their caregivers should seek emergency medical help for them immediately.
Diagnosis of alcohol intoxication
Good to know: If it is suspected that the person who has alcohol intoxication has consumed methanol, isopropanol or ethylene glycol rather than ethanol, an effort should be made to find out which one it was, as the treatment recommended in cases of methanol or ethylene glycol intoxication is different to that which is carried out for ethanol (see FAQs).
The diagnosis is usually made by considering the symptoms of the affected person and a physical examination. Alcohol levels can be measured in the blood or in the breath with a breathalyzer machine.
If doctors suspect that the affected person may be injured or have an underlying condition that is worsening the symptoms, other examinations may be carried out. Tests may be done, including X-rays or CT scans to check for fractures from falls and/or blows to head. Fingerstick tests for blood glucose should also be done, as the symptoms of severe hypoglycemia resemble those of alcohol intoxication.
Other disorders with symptoms that may be mistaken for alcohol intoxication include:
- Intoxication from recreational drugs, such as cocaine or opiates, or prescription drugs such as benzodiazepine or barbiturates.
- Carbon monoxide poisoning
- Hypoglycemia, low blood sugar
- Ketoacidosis, or high levels of acid in the blood
- Meningitis and encephalitis
- Alcohol withdrawal (see below)
- Cerebrovascular accidents, such as brain aneurysm or stroke
- Concussion or traumatic brain injury
- Subdural hematoma due to a blow to the head
- Severe dehydration
- Hyperthyroidism or hypothyroidism
- Alzheimer’s Disease
Treatment of alcohol intoxication
Treatment of ethanol alcohol intoxication usually involves fluids and management of nausea and vomiting. People who are mildly or moderately intoxicated will eventually process the alcohol, and will get better with time. Antiemetic drugs may be administered.
People with severe alcohol intoxication may need medical assessment or hospitalization to receive fluids through an IV line (a drip) and to manage any complications, such as seizures or difficulty breathing. In severe cases, the intoxicated person may need breathing support by intubation and ventilation.
Complications of alcohol intoxication
Hyponatremia, or a severe salt imbalance in the body, may occur in intoxicated people who vomit uncontrollably and cannot keep down electrolyte fluids or food. Hyponatremia can be fatal and must be treated in hospital.
Dysrhythmia, or “holiday heart”, is a condition in which the intoxicated person, though previously unaffected by heart problems, experiences heart arrhythmias after binge drinking.
Pancreatitis is a severe inflammation of the pancreas and can occur soon after binge drinking. It can be fatal and is considered a medical emergency. Chronic pancreatitis has a poor prognosis and can develop after multiple episodes of acute pancreatitis. Pancreatitis increases future risk of pancreatic cancer.
The lack of coordination, slow reaction time and lack of alertness associated with alcohol intoxication increase the intoxicated person’s risk of injury from unrelated causes, such as car accidents, falls and burns. Personality changes associated with alcohol intoxication also include impaired decision-making capabilities, unstable mood (emotional lability), loss of inhibitions and aggression. These may lead interpersonal violence, and injuries sustained in fights, as well as to potentially unsafe sexual behaviour.
Although alcohol withdrawal syndromes are associated with chronic alcohol use rather than acute intoxication, it is recommended that all people who are hospitalized with acute intoxication be screened for chronic use, dependence or alcoholism. Delirium tremens and seizures are possible in cases of abrupt cessation of drinking, when a person has been subject to sustained intoxication, and can be fatal.
Acute alcohol withdrawal, or hangover can occur after alcohol use. Symptoms of hangover include:
- Fatigue and weakness
- Excessive thirst
- Dry mouth
- Headaches and muscle aches
- Nausea and vomiting
- Stomach pain
- Poor or disrupted sleep
- Sensitivity to light and sound
- Dizziness and/or a sense that the room is spinning
Mild alcohol withdrawal may occur within six hours of cessation of alcohol use and includes symptoms such as tremors, weakness, sweating and elevated blood pressure, as well as alcoholic epilepsy.
Alcoholic hallucinosis occurs within twelve to 24 hours of abruptly ceasing alcohol use and has symptoms such as visual hallucinations, frightening dreams, and aggression.
Delirium tremens is the most severe form of alcohol withdrawal and requires care in an Intensive Care Unit, as it can be fatal. Symptoms of delirium tremens include confusion, anxiety attacks, hallucinations, depression, a pulse of greater than 120 beats per minute, and high fever.
See this resource for more information about alcohol withdrawal.
Prevention of alcohol intoxication
Alcohol intoxication can be avoided by drinking alcohol moderately or not at all. Strategies that help avoid alcohol intoxication include alternating alcoholic drinks with non-alcoholic drinks (ideally water), counting drinks, choosing beverages with lower alcohol content and eating a solid meal before drinking alcohol.
Q: What are the long-term effects of habitual alcohol use?
A: Chronic and/or habitual alcohol use, and alcohol dependence, have severe long-term effects on the body. Alcohol can affect the gastrointestinal system, heart, liver and pancreas, and can also cause neurological problems. Disorders associated with long-term alcohol use include:
- Peptic ulcers
- Portal hypertension, a disorder affecting the blood vessels in the liver and digestive system, a cause of Internal bleeding
- Esophageal varices, dilated veins in the lower esophagus, a cause of internal bleeding
- Fatty liver
- Cirrhosis of the liver
- Alcoholic hepatitis
- Chronic pancreatitis
- Blood coagulation problems
- Brain damage and alcoholic dementia
- Peripheral neuropathy, causing numb extremities
- Vitamin deficiencies and malnutrition
Q: How is methanol intoxication treated?
A: Methanol is extremely toxic, and if it is suspected that someone has ingested methanol, they must receive emergency medical care. In cases of methanol intoxication, immediate medical care is key if complications are to be avoided.
Methanol is metabolised by alcohol dehydrogenase, an enzyme, so treatment of methanol alcohol intoxication involves blocking the enzyme. This can be done with fomepizole: a high dose is given, followed by another in 12 hours. Ethanol has been used as an antidote for methanol, but this is not considered to be as safe or as effective as fomepizole treatment. Folic acid will also be administered during recovery from methanol intoxication. In cases of methanol intoxication, hemodialysis is often used as it can rapidly remove methanol from the blood.
Q: Is ethylene glycol toxic?
A: Ethylene glycol is toxic. Due to its sweet taste, there is particular risk of accidental ingestion by children and animals. Ethylene glycol intoxication is treated in the same way as methanol intoxication.
Other names for alcohol intoxication
- alcohol poisoning
- ethanol intoxication in adults
National Institute for Health and Care Excellence. “Guideline scope: Pancreatitis: diagnosis and management”. August 2016. Accessed 30 May 2018. ↩