How to tell if someone has drank alcohol?

September 21, 2025 •

4 min read

According to the World Health Organization, alcohol consumption is a major health concern, responsible for 5.3% of deaths globally. Identifying the signs of intoxication is crucial for personal safety and helping those in need, so knowing how to tell if someone has drank alcohol is an important skill.

Quick Summary

Detecting alcohol consumption involves looking for a combination of physical, behavioral, and attitudinal changes that become more pronounced with increased intake. Observable signs may include slurred speech, poor coordination, glassy eyes, and a flushed face, often accompanied by mood swings, lowered inhibitions, and impaired judgment. The key is to notice a deviation from the individual's normal state, as this can signal the presence of intoxication.

Key Points

Physical Indicators: Look for bloodshot or glassy eyes, a flushed face, or a disheveled appearance.
Behavioral Changes: Watch for lowered inhibitions, mood swings, or unusually loud and erratic behavior.
Impaired Speech and Coordination: Slurred speech, slow responses, stumbling, and clumsiness are common signs.
Alcohol Odor: The smell of alcohol on breath or clothing is a direct indicator of recent consumption.
Severity Matters: Recognize the difference between mild intoxication and severe symptoms like unresponsiveness or seizures, which require immediate medical attention.
Context is Key: Consider the individual's normal behavior, as some signs can be mimicked by fatigue or other conditions.
Know the Risks: Awareness of intoxication signs is vital for preventing harm to the individual and others, such as a DUI.

Recognizing Physical Signs of Alcohol Consumption

While some signs of intoxication are subtle, others become quite visible as a person's blood alcohol concentration (BAC) rises. These physical indicators are often the most immediate and objective evidence that someone has been drinking.

Eye and Facial Changes

One of the most classic signs of recent alcohol consumption is how it affects a person's eyes and face. Alcohol dilates the blood vessels, which can lead to a few telltale signs:

Bloodshot or Glassy Eyes: The dilation of tiny blood vessels makes the eyes appear red or glassy.
Droopy Eyelids: The depressant effect of alcohol can relax the muscles around the eyes, causing the lids to droop.
Flushed Face: Increased blood flow to the skin, particularly on the face, can cause a reddish, flushed appearance.
Blank Stare: Intoxicated individuals may have a dazed or unfocused expression, indicating a lack of alertness.

Changes in Coordination and Movement

Alcohol is a central nervous system depressant, and as it takes effect, it directly impacts a person's motor skills and coordination. This can be observed in their movements and gait.

Swaying, Staggering, or Stumbling: Impaired balance is a common symptom, leading to an unsteady walk or difficulty standing still.
Fumbling or Clumsiness: Trouble with fine motor skills can lead to dropping things, fumbling with keys, or general clumsiness.
Difficulty with Basic Tasks: Simple actions, such as finding their mouth with a glass or lighting a cigarette, can become surprisingly difficult.

The Smell of Alcohol

Perhaps the most direct and unmistakable sign is the odor of alcohol. The body metabolizes alcohol, and some of it is expelled through the pores and breath. The smell can cling to a person's breath, skin, and even their clothes. It is important to note that some people may try to mask this odor with mints, gum, or perfume, so it should be considered alongside other signs.

Observing Behavioral and Attitudinal Shifts

Beyond the physical indicators, alcohol has a profound effect on a person's mental state, inhibitions, and overall behavior. These changes can be particularly revealing, especially when contrasted with the individual's normal personality.

Altered Judgment and Inhibitions

Alcohol impairs the part of the brain responsible for judgment and decision-making, leading to behaviors that are out of character for the individual.

Risky or Impulsive Behavior: An intoxicated person might take risks they normally wouldn't, such as driving impaired, making inappropriate advances, or getting into fights.
Loudness or Talkativeness: The individual may become louder and more boisterous than usual, sometimes switching abruptly between being loud and quiet.
Erratic Emotional States: Mood swings are common, with a person potentially shifting from happy and euphoric to sad, angry, or argumentative in a short period.

Speech and Communication Issues

Alcohol disrupts the communication between the brain and the muscles, which often manifests in speech problems.

Slurred Speech: This is a classic sign of intoxication, where words are difficult to form and articulation is unclear.
Rambling or Repetitive Conversation: An intoxicated person may lose their train of thought, ramble incoherently, or repeat themselves frequently.
Slowed Responses: Their reaction time may be slower, leading to delays in responding to questions or comments.

Differentiating Between Mild and Severe Intoxication

Not all signs are equal, and the severity of intoxication can be gauged by the type and intensity of the symptoms. It is vital to recognize when intoxication becomes a medical emergency.


Feature	Mild Intoxication	Severe Intoxication (Poisoning)
Appearance	Mildly flushed face, slightly glassy eyes.	Blue-tinged or pale skin, seizures, unresponsive.
Coordination	Minor swaying or unsteadiness, slight clumsiness.	Inability to walk or stand, loss of motor control.
Speech	More talkative, slightly slurred, potentially louder.	Very slurred or incoherent speech, slowed or difficulty breathing.
Attitude	Relaxed, euphoric, lowered inhibitions.	Confusion, aggression, emotional instability, inability to remain conscious.
Other Signs	Increased urination, sweating.	Vomiting, slowed heart rate, low body temperature.

Recognizing Alcohol Poisoning

Severe intoxication can lead to alcohol poisoning, a potentially life-threatening condition. Knowing the signs is crucial for knowing when to seek immediate medical help.

Slowed or Irregular Breathing: Fewer than eight breaths per minute or pauses between breaths.
Pale or Bluish Skin: Especially around the lips, fingertips, and nail beds, indicating a drop in body temperature.
Hypothermia: The body temperature drops dangerously low.
Vomiting and Seizures: Uncontrollable vomiting or convulsions are serious red flags.
Unconsciousness or Unresponsiveness: The person cannot be awakened, indicating a dangerously high BAC.

The Importance of Context

While these signs can be strong indicators, context is always important. Some medical conditions, medications, or extreme fatigue can mimic symptoms of intoxication. However, when multiple signs appear together, especially with a history of alcohol use, it is a strong indication of recent consumption. If there is any doubt or concern for a person's health and safety, it is always best to err on the side of caution. For more information on health and safety, consider visiting the National Institutes of Health website.

Conclusion

Understanding how to tell if someone has drank alcohol is a valuable skill that can help protect both individuals and those around them. By paying attention to a combination of physical and behavioral signs, such as slurred speech, poor coordination, and mood changes, you can gauge a person's level of intoxication. Recognizing the more severe signs, like slowed breathing and unresponsiveness, is critical for identifying a potential medical emergency like alcohol poisoning. The ability to observe these signs and act responsibly is a crucial part of promoting safety and responsible alcohol consumption.

Frequently Asked Questions

No, you cannot always tell by breath alone. While the smell of alcohol on a person's breath is a common sign, it can be masked by breath mints, gum, or other strong odors. For an accurate assessment, it is important to consider multiple signs and not rely on breath alone.

While fatigue can cause some similar symptoms, such as irritability or a dazed look, intoxication often presents a wider range of symptoms simultaneously. Look for the combination of slurred speech, impaired coordination, and behavioral shifts, which are less common with simple tiredness.

The legal limit for blood alcohol concentration (BAC) varies by location, but 0.08% is a common standard for driving. However, some individuals can be visibly intoxicated below this limit, especially with lower tolerance levels. BAC is a legal measure, but outward signs of impairment can appear at different levels for different people.

Yes, intoxication progresses through stages, with symptoms becoming more pronounced as more alcohol is consumed. These stages range from euphoria and lowered inhibitions to significant impairment of judgment and coordination, and eventually to life-threatening conditions like a stupor or coma.

Alcohol is a depressant that affects the frontal lobe of the brain, which is responsible for judgment and rational decision-making. This can lead to lowered inhibitions, increased risk-taking behavior, and poor choices that a person would not normally make.

Signs of alcohol poisoning include severe confusion, vomiting, seizures, slowed or irregular breathing, pale or bluish skin, and unresponsiveness. This is a medical emergency and requires immediate professional help.

People with a higher tolerance to alcohol or those who drink regularly can sometimes be better at masking the physical signs of intoxication. However, their reaction time and coordination are still impaired, making them potentially more dangerous. It is important to look for subtle signs and not be misled by a person's attempts to appear sober.