When a person consumes alcohol, the full effects may take some time to become apparent. Depending on a number of factors—including the amount consumed, the rate of consumption, gender, body weight, and whether the drinking episode took place on an empty or full stomach1—there are somewhat predictable stages of alcohol intoxication through which the individual may progress as their drinking continues.
A chart breaking down the progressive effects of intoxication as blood alcohol content rises can be used to estimate just what increasing levels of drinking could do to the body and the individual’s judgment and behaviors.2 It’s important to remember that the same number of drinks will not produce the exact same BAC among different individuals. A person’s size, metabolism, ethnicity, and other factors can impact how they are affected by alcohol.1
Stage 1: Sobriety, or Subclinical Intoxication
At a BAC of 0.01-0.05, the individual is unlikely to appear intoxicated, though certain tests may detect impairment.2 Depending on the individual, judgment and reaction time may be slightly impaired.
One drink will generally result in a BAC within this range for both males and females, with the exception of women weighing under 100 pounds, according to a chart from Loyola University Maryland.3
Stage 2: Euphoria
The second stage of intoxication, referred to as euphoria, occurs between 0.03 and 0.12 BAC (which may correspond to roughly 1-4 drinks for a woman or 2-5 for a man, depending on size).2,3 In this stage, the individual may feel more confident, may be more talkative and animated, and may feel slightly euphoric. Inhibitions also begin to decline.2 Most people refer to this stage as being “tipsy.”
While many of the effects of alcohol may be pleasurable to the drinker, the negative effects of alcohol, such as impaired judgment, memory, and coordination begin to appear at this time, as well.2 In this stage, a person’s motor responses may be significantly more delayed than at a lower BAC.
Based on information from the National Highway Traffic Safety Administration, alertness is decreased, the individual begins having trouble processing information, and they do not detect danger as quickly.4 A driver is approximately 4 times more likely to get into a vehicle collision than a driver with a BAC of zero, and driving with a BAC of 0.08 or higher is illegal and can result in a DUI arrest.4
Stage 3: Excitement
Having a BAC between 0.09 and 0.25 lands a person into the third stage of intoxication: excitement. They may begin to experience emotional instability, a lack of critical judgment, and a significant delay in reaction time. They may start slurring their speech.2 They may also experience:2
- Impaired perception and memory.
- Vision issues, including decreased peripheral vision, blurriness, and delayed glare recovery.
- Loss of balance.
- Nausea and vomiting.
Those around the person will likely notice that they are visibly drunk.
Stage 4: Confusion
Someone with a BAC level of 0.18 to 0.30 is in the confusion stage, characterized by emotional upheaval and disorientation. Coordination is markedly impaired, to the extent that the person may not be able to stand up, may stagger if walking, and may be very dizzy.2
Those in this stage of intoxication are highly likely to forget things that happen to or around them. “Blacking out” (losing memory of events that occurred while drinking) without actually passing out can happen at this stage.5 In addition, a person may have and markedly increased pain threshold, meaning they could injure themselves and not feel the effects until later.2
Stage 5: Stupor
Stupor can occur at a BAC between approximately 0.25 and 0.40. Someone in this stage is extremely intoxicated and in dangerous territory, as they are at great risk of alcohol poisoning and death.6 They have likely lost a significant amount of motor function, are not responding to stimuli (or responding very slowly) and may be:2
- Unable to stand or walk.
- Stuporous or completely passed out.
- Unable to voluntarily control certain bodily functions, such as maintaining continence.
Someone in this stage should get medical help. Individuals left to “sleep it off” may end up suffering from slowed breathing or respiratory arrest or may choke on their own vomit. Other risks include hypothermia, arrhythmia, and seizures.7
Stage 6: Coma
A person who has reached 0.35-0.45 BAC is at significant risk of lapsing into a coma. Respiration and circulation are severely depressed, motor response and reflexes are markedly decreased, and the person’s body temperature drops. The person who has reached this stage is at risk of death.2
Stage 7: Death
At about 0.45 BAC or above, many are unable to sustain their vital life functions, and the risk of respiratory arrest and death is significant. Note that death is also possible at lower BACs.7
Understand the Risks
Scaling these risky BAC thresholds is not as difficult as some might think. Because it takes time for alcohol to have an effect on the body, consuming the large amounts required to reach these BAC levels can occur while the person is still reasonably sober.
Because the amount of alcohol needed to reach various states of intoxication can vary depending on the individual, what might be a fatal dose for one person may not be for another.
A habitual or chronic drinker may develop tolerance to the effects of alcohol and may not experience the symptoms or show the signs of intoxication as readily as those who do not drink often. A study from Alcohol and Alcoholism found a range of BAC levels—from 0 to 0.4—in people admitted to emergency departments with suspected alcohol intoxication; furthermore, the outward signs of intoxication seemed at least partly based on their tolerance for alcohol and how regularly they drank. In other words, the magnitude of observable drunkenness doesn’t always correspond well with BAC measurements, particularly so with chronic drinkers. This phenomenon could result in people, including emergency room staff, to misjudge the person’s actual intoxication level, as their BAC may be much higher than their outward appearance would suggest.8
Heavy alcohol consumption comes with a huge range of risks. If you find yourself drinking heavily and commonly reaching the later stages of drinking associated with severe risks like blacking out and suppressed respiration, you may need help. Research-based treatment that provides the needed skills and tools to manage alcoholism and maintain sobriety into the future can help people lessen their risk of relapse and overdose.
You May Also Be Interested In
- Bowling Green State University. (n.d.). Factors that Affect Intoxication.
- Dubowski, Kurt. (2019). STAGES OF ACUTE ALCOHOLIC INFLUENCE/INTOXICATION BLOOD ALCOHOL CONCENTRATION grams/100 mL STAGE OF ALCOHOLIC INFLUENCE CLINICAL SIGNS/SYMPTOMS.
- Loyola University Maryland, (n.d.). Calculate Your Blood Alcohol Level.
- National Highway Traffic Safety Administration. (2016). The ABCs of BAC.
- UC San Diego Health Services. (n.d.). Blood Alcohol Content and YOU.
- National Institute on Alcohol Abuse and Alcoholism. (2018). Understanding the Dangers of Alcohol Overdose.
- National Institute on Alcohol Abuse and Alcoholism. (n.d.). Facts About Alcohol Overdose (or Alcohol Poisoning).
- Kalen N. Olson, Stephen W. Smith, Julie S. Kloss, Jeffrey D. Ho, Fred S. Apple, Relationship Between Blood Alcohol Concentration and Observable Symptoms of Intoxication in Patients Presenting to an Emergency Department, Alcohol and Alcoholism, Volume 48, Issue 4, July/August 2013, Pages 386–389.