What is Blood Alcohol Concentration (BAC)?

The amount of alcohol in a person’s body is measured by the weight of the alcohol in a certain volume of blood. This is called the blood alcohol concentration, or “BAC.”

Alcohol is absorbed directly through the walls of the stomach and the small intestine, goes into the bloodstream, and travels throughout the body and to the brain.

Factors that affect my BAC

The number of drinks. The more you drink, the higher the BAC. Take note of the size of the glass or container the drink is in. It may be more than one serving.

Strength of drinks.
No drink is “safer” than another. One 12-ounce beer has the same alcohol content as a 5-ounce glass of wine or 1 ¼ -ounce shot of 80-proof liquor.

How fast you drink. When alcohol is consumed quickly, you will reach a higher BAC than when it is consumed over a longer period of time. Take small sips of your drink. Try alternating drinks with a soda or water.

Your gender. Women generally have less water and more body fat per pound of body weight than men. Alcohol does not go into fat cells as easily as other cells, so more alcohol remains in the blood of women.

Your weight. The more you weigh, the more water is present in your body. This water dilutes the alcohol and lowers the BAC.

Food in your stomach. Absorption will be slowed if you’ve had something to eat. Try eating high protein foods like cheese and peanuts

Emotional state. When a person is emotional or stressed, their body tends to divert blood away from the stomach and small intestines, and instead moves it to the muscles. This reduced blood flow slows down the absorption of the alcohol in the body.

Medication. Use alcohol carefully when taking prescription or even over-the-counter medication. Some medications can dramatically increase the effects of alcohol.


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Drink as a group, be responsible as a group

When you're out with friends, you're not just responsible for yourself. If you suspect that anyone in your group is impaired, join together to keep that person from driving.