Medically reviewed by Cameron White, MD, MPH
Written by Jamie Eske
Alcohol intoxication refers to a temporary condition that occurs when a person drinks an excess of alcohol at one time.
Alcohol intoxication causes physical and behavioral symptoms that range from mild to severe.
Severe alcohol intoxication — or alcohol poisoning — is a dangerous condition that requires immediate medical attention.
Although people can safely consume alcohol without experiencing immediate adverse health effects, long term alcohol consumption can jeopardize overall health.
The Department of Health and Human Services classifies alcohol as a carcinogen, a substance that plays a role in causing cancer. The medical community has linked alcohol with numerous types of cancer, such as cancers of the mouth, larynx, and esophagus.
Keep reading to learn more about alcohol intoxication, including its causes, symptoms, and treatments.
What is alcohol intoxication?
Alcohol intoxication occurs when a person drinks an excess of alcohol in one period.
A standard serving of alcohol in the United States is 0.6 fluid ounces (fl oz) or 14 grams (g) of pure alcohol. This translates to the following single servings of standard alcoholic drinks:
- 12 fl oz of beer with a 5% alcohol content
- 5 fl oz of wine with a 12% alcohol content
- 1.5 fl oz of a distilled spirit with a 40% alcohol content
The liver removes alcohol from the bloodstream, but it can only filter out so much at once.
The rate at which the body metabolizes alcohol varies from person to person, depending on factors such as:
- body weight
- body size
- health status
- alcohol tolerance
When a person drinks more alcohol than their liver can process, ethanol molecules start accumulating in the body. This can damage tissue cells and organs.
The symptoms of alcohol intoxication range from mild to severe, depending on how much alcohol a person consumes and how quickly their body metabolizes it.
These symptoms often occur in stages, depending on how intoxicated a person is. The table below shows common symptoms at each level of alcohol intoxication.
This data comes from the National Institute on Alcohol Abuse and Alcoholism. It includes information about blood alcohol concentration or content (BAC) — a common way to measure intoxication for medical or legal purposes. BAC refers to how much alcohol is in the bloodstream.
Intoxication Stage BAC Symptoms
Mild 0.00% to 0.05% mild impairments
to speech and memory
mild impairments to balance and coordination
mild impairments to attention
perceived beneficial effects, such as relaxation
Moderate 0.06% to 0.15% increased impairments to speech and attention
increased impairments to balance and coordination
moderate memory impairments
increased risk of aggression, in some people
increased risk of injury to self and others
significant impairments to skills
necessary for driving increase in perceived
beneficial effects of alcohol, such as relaxation
Severe 0.16% to 0.30% significant impairments to speech and memory
significant impairments to coordination
and balance significant impairments to judgment
and reaction time dangerous impairments to
skills necessary for driving vomiting blackouts
(amnesia) loss of consciousness
Life threatening 0.31% to 0.45% loss of consciousness
danger of a life threatening alcohol overdose
suppression of vital functions, leading to a
significant risk of death
People can get individualized BAC estimates using this calculator.
In every U.S. state, it is illegal to drive with a BAC of over 0.08%. A person who drives with a higher BAC is at risk of arrest.
How does alcohol cause intoxication?
In alcoholic drinks, a chemical compound called ethanol is responsible for the symptoms associated with intoxication. Numerous commercial and household products, such as mouthwash, perfume, and gasoline, also contain ethanol.
When a person drinks alcohol, ethanol passes through the digestive system and enters the bloodstream through the linings of the stomach and intestines. If an individual drinks alcohol on an empty stomach, their BAC usually peaks within 30–90 minutes.
Once ethanol is inside the bloodstream, it can travel throughout the body, affecting various functions.
Ethanol interferes with the balance of neurotransmitters in the brain by increasing the amount of gamma-aminobutyric acid. This amino acid, often called GABA, reduces central nervous system activity.
Ethanol also increases levels of adenosine, an inhibitory neurotransmitter that promotes sleep.
People may feel euphoric while drinking alcohol because ethanol stimulates the release of dopamine, a feel-good chemical in the brain. This effect on the brain’s dopamine system can lead to alcohol dependence.
Alcohol also interferes with several other bodily functions, such as:
- temperature regulation
- balance and coordination
- heart rate
- blood pressure
- decision making
- reproductive health
- immune function
Learn more about the short- and long-term effects of alcohol consumption here.
Signs in others
A person can usually tell when they are intoxicated, but it may be challenging to spot the signs in others.
To gauge another person’s level of intoxication, try looking for the following signs:
- a loss of coordination, such as stumbling or swaying
- flushing of the face
- bloodshot eyes
- louder speech than usual
- slurred speech
- damp or clammy skin
- mood swings or personality changes, such as aggression or depression
- slowed reflexes
- a loss of consciousness
People cannot treat severe alcohol intoxication — or alcohol poisoning — at home. If anyone shows signs of severe intoxication, contact emergency services immediately. In the U.S., call 911.
Follow these steps while waiting for professional assistance:
- If the person is conscious and can swallow, give them water, and have them lie on their side. This helps prevent the person from choking if they vomit.
- If the person is unconscious, turn them on their side.
In the emergency room, a doctor will check their BAC and look for other signs of alcohol poisoning, such as a slow heart rate and low blood sugar and electrolyte levels.
A healthcare professional will monitor the person’s vital signs while they recover. The doctor or nurse may also:
- administer fluids intravenously — with an IV — to prevent dehydration
- administer vitamins and sugar to treat low blood sugar
- insert a breathing tube to open the airways and provide more oxygen to the body
- pump the stomach to rid the body of excess alcohol
Alcohol intoxication occurs when a person drinks an excess of alcohol in a short period.
A low level of alcohol intoxication causes mild symptoms, while severe intoxication, or alcohol poisoning, can be life threatening. It requires immediate medical attention.
People can survive alcohol poisoning if they receive appropriate treatment. However, recovery sometimes takes several weeks or months.