- What is alcohol intoxication?
- Other names for alcohol intoxication
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 products
Methanol is extremely toxic. If consumed, even ten milliliters of methanol can cause blindness, and consuming thirty milliliters is potentially fatal. Methanol poisoning requires emergency medical treatment, and if it is suspected that someone has ingested methanol, they should receive medical attention as soon as possible.
Causes of alcohol intoxication
In adults, alcohol intoxication usually results from consuming commercial alcoholic beverages containing ethanol. 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
- Certain 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 metabolize 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 wellbeing and increased social confidence, may be considered pleasant. However, certain 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.
Alcohol intoxication is usually treated with fluids, and many people experience no lasting health consequences from being drunk, 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.
In severe cases, alcohol intoxication may lead to conditions that can temporarily impair the functioning of the pancreas or liver. This impairment may become chronic if it happens repeatedly. Heavy alcohol intoxication can result in serious health effects and may lead to complications and even death.
Risk of alcohol intoxication
Drunkenness is caused by an excessive intake of alcohol; it is a very common condition.
Alcohol is a central nervous system depressant, a type of substance that causes the muscles to relax and dampens the body’s reaction to stimuli.  The absorption rate of alcohol and associated risk of alcohol intoxication depends not only on the quantity of alcohol, but also on a number of other factors, including 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(s) ingested
- The period of time over which the alcohol was ingested
- Whether the affected person had eaten before or during the period in which they ingested alcohol
- Whether the affected person is well-hydrated or not
- 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
- 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 metabolized. These include many commonly-prescribed and over-the-counter medications used to treat a wide variety of conditions. The prescribing physician or dispensing pharmacist will be able to give advice about whether any particular drug will affect alcohol metabolism.
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 differences in body size and variations in each individual’s 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 alcohol poisoning, 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. If you choose to consume alcohol, it is best to spread your drinking out equally over a few days. The World Health Organization recommends that men drink no more than two standard drinks, or 24 grams, of alcohol a day, and that women drink no more than one standard drink, or 12 grams, a day. There is an increasing body of research that suggests that consuming any alcohol at all may be harmful.
Signs and symptoms of alcohol intoxication
The symptoms experienced depend on the level of alcohol in the blood, and whether the person drinks alcohol regularly.
Early effects of alcohol intoxication may include:
- Rapid heartbeat
- Feelings of wellbeing and confidence
- Reddening of the skin or flushing of the face
- Impaired motor coordination
Symptoms of worsening alcohol 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.
If you are concerned that you or someone else may have alcohol intoxication, you can do a free symptom assessment using the Ada app.
Levels of alcohol intoxication
Because everyone processes alcohol slightly differently, the amount of alcohol that can cause mild, moderate or severe intoxication also varies. However, broadly, the levels of alcohol intoxication can be grouped as follows:
- Mild intoxication: between 0 mg and 50 mg
- Moderate intoxication: between 50 mg and 200 mg
- Severe intoxication: 200 mg and upward
- Extreme intoxication: 400 mg and upward
Levels of alcohol intoxication are usually expressed as mg / dL, or milligrams per deciliter. A deciliter is 100ml of blood, so, for example, mild intoxication occurs at a level of 20mg of alcohol per 100ml of blood. But, because everyone processes alcohol a little differently, and the results of blood alcohol tests may not be easily available outside a medical setting, it may be easier to determine how drunk someone is by the symptoms they show or report.
If you are concerned that someone you know may have alcohol intoxication, you can assess their symptoms for free using the Ada app.
Mild alcohol intoxication
- A feeling of tranquility and relaxation
- Mild feelings of sedation
- Impairment in tasks requiring skill and/or fine motor coordination
Moderate alcohol intoxication
- Increasing trouble with fine motor coordination
- Uncontrolled eye movements
- Clumsiness and unsteady gait
- Slowed reaction time
- Slurred speech
- Impaired judgement
- Altered perception of the environment
- Changes in mood, behavior and personality
- Loss of inhibitions
- Memory impairment
Severe alcohol intoxication: alcohol poisoning
- 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), 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. For more information on death as a result of alcohol poisoning, see the section on complications below.
- Smell of alcohol on breath or clothing
- Slow breathing
- Enlarged pupils
- Faster-than-usual eye movements
- Redness of the face
- Incoherent speech
- Lack of alertness
- Semi-consciousness or lack of responsiveness
When to seek medical care
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 minimize 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 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
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 performing 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. Imaging 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 can 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 benzodiazepines 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 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.
Good to know: This section applies to ethanol poisoning, as ethanol is the type of alcohol found in most commercial alcoholic beverages. For treatment of methanol or ethylene glycol intoxication, see the FAQs
Treating alcohol intoxication at home: first aid measures
People affected by acute alcohol intoxication can sometimes be treated at home, although medical advice should be sought as soon as possible in cases where the affected person:
- Is not fully conscious
- Does not seem to be breathing properly
- Is injured, for example after falling down
- Has another medical condition, such as diabetes, that is likely to affect their recovery
This is more likely to be the case if the affected person is moderately or seriously intoxicated.
People who are slightly intoxicated generally do not need medical care. However, blood alcohol levels continue to rise even after the affected person has stopped consuming alcohol, as alcohol still in the stomach and intestines is metabolized. For this reason, someone who is only moderately intoxicated when they stop drinking may become seriously intoxicated afterwards.
Those around a drunk person should take steps to ensure that they are safe and monitor them for injuries, unconsciousness, severe vomiting and signs of difficulty breathing. Someone with first-aid experience should check the affected person’s pulse. If any of these appear, seek medical care without delay. Likewise, seek urgent medical care if the person’s condition does not improve.
Good to know: If the affected person is breathing, move them into a stable position on their side and wait with them until the ambulance arrives. If they are not breathing, check that their throat is clear. If it is not, remove the obstruction. If they do not begin to breathe once their throat is clear, begin mouth-to-mouth resuscitation.
If it is suspected that the person has consumed methanol or ethylene glycol rather than ethanol, the condition cannot be managed at home, and emergency medical care should be sought.
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. Acute pancreatitis 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 car accidents, falls, burns and other accidents. Personality changes associated with alcohol intoxication also include impaired decision-making capabilities, unstable mood (emotional lability), loss of inhibitions and aggression. These may lead to interpersonal violence, and injuries sustained in fights, as well as to potentially unsafe sexual behavior.
Death from alcohol intoxication
Death from alcohol intoxication becomes possible at approximately the point at which 500mg of alcohol has been consumed, although this point can be lower, depending on the person involved. Alcohol suppresses the functioning of the brain and central nervous system, and severe intoxication can cause serious impairment of functions like breathing and consciousness. If the condition is left untreated, death as a result of alcohol intoxication can result from a number of reasons, including:
- Respiratory depression as a result of depression of the central nervous system, leading to insufficient oxygen intake
- Aspiration of vomit leading to choking can occur when the affected person has become unconscious
- Injury or accident as a result of slowed reaction times, lack of coordination, and lack of alertness
- Dehydration: alcohol is a diuretic and can also cause fluid loss through vomiting. As someone who is semi-conscious or unconscious may not be able to drink, they may become severely dehydrated and possibly die.
- Heart attack as a result of irregular heart rhythms
Good to know: People who binge drink rapidly – that is, who consume very large amounts of alcohol quickly, for example on a bet or in a competition – risk consuming a fatal dose of alcohol even before signs of intoxication become evident.
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. It is also possible to experience alcohol withdrawal after using alcohol for only a short period, although when this is the case, the symptoms are likely to be temporary and have no lasting effect.
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, a condition in which withdrawal from alcohol causes seizures.
Alcoholic hallucinosis may occur 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.
Prevention of alcohol intoxication
Alcohol intoxication can be avoided by drinking alcohol moderately or not at all. Strategies that may help avoid alcohol intoxication include alternating alcoholic drinks with non-alcoholic drinks (ideally water), counting drinks carefully, 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, such as folate deficiency, and malnutrition
If you are concerned that you or someone you know may have developed one of these conditions, you can do a free symptom assessment whenever you like using the Ada app.
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 metabolized by alcohol dehydrogenase, an enzyme, and treatment of methanol alcohol intoxication involves blocking the enzyme. This can be done with fomepizole: a high initial 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. It is found in common household substances such as antifreeze. 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.
Q: What is delirium tremens?
A: Delirium tremens is a condition that usually occurs with alcohol withdrawal rather than with alcohol intoxication. It is a very severe form of alcohol withdrawal and can involve seizures, shaking, very high blood pressure, confusion, anxiety, depression, hallucinations, fever, and very rapid heartbeat.
Q: Can alcohol intoxication cause seizures?
A: Alcohol use is associated with a higher risk of seizures. It is thought that epilepsy is more common among people who are dependent on alcohol, and it is known that alcohol withdrawal can cause seizures. In addition, head injuries that may be sustained during acute alcohol intoxication can sometimes lead to seizures.
Q: Can alcohol intoxication cause heart arrhythmia?
A: Yes. A condition causing heart arrhythmia, known as holiday heart, can affect people who binge drink, even if they do not have existing heart problems. The condition gets its name from the fact that many people drink more alcohol during holidays than they ordinarily would. Holiday heart causes atrial fibrillation, when the heart’s upper chambers, the atria, fail to coordinate with the lower chambers, the ventricles.
Although the prognosis of holiday heart does depend on the general heart health of the affected person, it usually resolves on its own. However, it can reoccur. It tends to be more severe, and the prognosis is worse, in people who are already heavy drinkers.
Q: Can alcohol intoxication cause death?
A: Yes. Serious alcohol intoxication can cause death, usually due to the effect alcohol has on the respiratory system. Very rarely, people who are allergic to alcohol may experience anaphylactic shock, which can be fatal if untreated.
Q: Is it possible to be allergic to alcohol?
A: Yes. However, it is a relatively uncommon allergy. In people who are allergic, however, as little as a sip of beer or wine can lead to rashes, difficulty breathing, stomach pain or cramps. Alcoholic drinks typically also contain other substances, such as preservatives or flavorings, which can themselves cause allergic reactions. Being intoxicated by alcohol can also increase the likelihood of experiencing a severe allergic reaction from other causes, such as accidental ingestion of nuts or shellfish. It is difficult to diagnose alcohol allergy, as skin tests often do not show the allergy.
Q: Is facial flushing after drinking alcohol a sign of allergy?
A: No, it is not. Facial flushing after drinking alcohol is a sign of the accumulation of acetaldehyd, a byproduct of alcohol metabolism, in the body. This accumulation is caused by a deficiency of acetaldehyde dehydrogenase, an enzyme that converts acetaldehyde into acetic acid, a harmless byproduct that is less toxic and more easily excreted than acetaldehyde. The flush reaction has a genetic cause, and it is particularly common among people of East Asian descent. There is some evidence that people who experience flushing after drinking alcohol may be at increased risk of esophageal cancer. 
Q: Can alcohol intoxication be treated with first aid?
A: Yes, in cases of mild or moderate intoxication. See the section on treatment. However, it is important to monitor people who are intoxicated and seek professional medical help if their condition does not improve.
Q: Is naloxone effective against alcohol intoxication?
A: No. It is thought that naloxone only works to reverse the effects of overdose resulting from opioids such as heroin, methadone, hydrocodone, morphine or codeine. It is not effective against benzodiazepines, sedatives, or alcohol.
Q: Is alcohol intoxication a criminal offence?
A: In some states and countries, alcohol intoxication itself is a criminal offence. Driving while under the influence of alcohol is also a criminal offence in most countries. Some countries treat being intoxicated in public as an offence, especially if it leads to accidents, assaults or fighting. Consuming alcohol in certain places or at certain times of day may also be regulated. Many countries also have regulations about the minimum age at which a person can legally purchase alcohol and at which age they can be admitted to establishments that serve alcoholic beverages. Because the exact laws and legislations that govern alcohol use vary greatly, it is best to check which regulations apply in your particular location.
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. ↩
National Institute on Alcohol Abuse and Alcoholism. "Alcohol Overdose: The Dangers of Drinking Too Much". October 2015. Accessed 28 October 2018. ↩
College Drinking Prevention. "Facts About Alcohol Overdose (or Alcohol Poisoning)". Accessed 28 October 2018. ↩
Gastroenterology Nursing. “Asian Flushing: Genetic and Sociocultural Factors of Alcoholism Among East Asians”. September 2014. Accessed 11 January 2019. ↩
PLoS Medicine. “The Alcohol Flushing Response: An Unrecognized Risk Factor for Esophageal Cancer from Alcohol Consumption”. March 2000. Accessed 11 January 2019. ↩