Blood Alcohol Content Effects

 Many Americans enjoy a leisurely drink after a long day at work or when they receive a break from the kids. Whatever the occasion, alcohol is a normal part of life in the United States, but it is important to understand the various impacts of alcohol consumption. I will discuss increasing blood alcohol content effects on the body, behavior, and the brain.

Blood alcohol content effects change as the level of blood alcohol increases. I will discuss the impact of alcohol on the body at various levels of intoxication, then I will describe some general effects that alcohol can have on the body.

At .02% blood alcohol concentration (BAC), individuals may experience slight body warmth, a decline in visual functions, and bodily relaxation.

At .05% BAC, individuals may experience loss of small muscle control, reduced reaction time, and reduced coordination.

At .08% BAC, individuals may experience poor muscle coordination and impaired perception.

At .10% BAC, individuals may experience slurred speech, poor coordination, and a clear deterioration of reaction time.

Finally, at .15% BAC, individuals may experience vomiting, a major loss of balance, and far less muscle control than normal.

High levels of BAC can lead to alcohol poisoning. Pregnant women who consume alcohol may experience a miscarriage, a stillbirth, or the fetus may develop a fetal alcohol spectrum disorder.

In the long term, heavy alcohol use can cause high blood pressure, heart disease, stroke, liver disease, digestive problems, cancer, learning and memory problems, and mental health problems, including anxiety and depression.


It is easy to see how blood alcohol content affects behavior as well.

At .02% BAC, individuals may exhibit some loss of judgment, a decreased ability to multitask, and altered mood.

At .05% BAC, individuals may exhibit exaggerated behavior, impaired judgement, and a release of inhibition.

At .08% BAC, individuals may exhibit impaired judgment, self-control, and reasoning, a reduced ability to concentrate, and a reduced capacity to process information.

At .10% BAC, individuals may exhibit slurred speech and slowed thinking.

Increasing blood alcohol levels are associated with drinking and driving. Young people who drink are the most likely to drive while intoxicated or to ride in a vehicle while the driver is intoxicated.

Alcohol consumption is also a risk factor for violent behavior, specifically sexual assault, domestic violence, suicide, and even homicide. Men are more likely than women to have been drinking prior to committing suicide.

Some individuals who drink heavily, especially on college campuses, may engage in risky sexual behaviors such as unprotected sex or sex with multiple partners. This can result in unwanted pregnancy or the transmission or STIs.

The Brain

If blood alcohol content effects are this pronounced on the body and on behavior, then alcohol must have a significant impact on the brain. These effects can be short term or long term.

Memory impairment is a common short term effect of increasing blood alcohol content. Large amounts of alcohol can cause a full blackout, an experience in which the consumer does not remember anything for a period of time. This is common and can happen even to drinkers who are not dependent on alcohol. Often, people will participate in dangerous activities while they are at this level of intoxication, and then they will not be able to remember it. Females are at greater risk for blackouts than males.

Brain shrinkage, a sign of brain damage, is a long term effect of heavy alcohol consumption. It often results in learning and memory problems. Some studies show that women’s brains may shrink at a faster rate than males’ brains, but the research is inconclusive.

Other studies show that excessive alcohol consumption can interfere with the growth of new brain cells. Humans continue to grow new brain cells into adulthood, through a process called neurogenesis. Heavy alcohol use seems to prevent or slow this process.

Finally, brain damage from liver disease is another major effect of long term alcohol consumption. This may be caused by thiamine (vitamin B1) deficiency. If the liver is damaged, the brain may not be able to receive adequate nutrients. Thiamine deficiency results in mental confusion, poor muscle coordination, and forgetfulness. Some individuals may experience a shortened attention span, anxiety and depression, and even coma.

Wrapping it up

Increasing blood alcohol content effects can have devastating consequences in the short term if they are not properly managed. Individuals may become victims or perpetrators of sexual assault, other violent acts, or drinking and driving. In the long term, alcohol consumption can have a significant impact on the brain and the body. It is important to understand the effects of alcohol and make educated decisions about alcohol consumption. Be sure to calculate your BAC before drinking and driving, or if you feel you have had too much to drink.

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