If you understand how alcohol can affect you, it may help you to drink responsibly.
The following factors influence how people respond to alcohol, according to the National Institutes of Health and the American Medical Association.
The extent of alcohol's effect on the central nervous system depends upon how much is in your blood and how much blood you have. This is because alcohol is distributed through the body by the water in your bloodstream, according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA). The more water in your blood, the more diluted the alcohol will be.
Generally, the lower your body weight, the less blood and water you have. So, smaller people usually have a higher ratio of alcohol in their blood if they drink the same amount a heavier person drinks.
For most people, intoxication occurs after two to three drinks, with less intake in a lighter person. An average drink is 12 ounces of beer, 5 ounces of wine or 1.5 ounces of 80-proof liquor. Keep in mind that the alcohol content of different types of beer, wine and distilled spirits can vary substantially.
Men generally can drink more alcohol than women of the same size before they show its effects. This is because women have less body water than men of similar body weight, so women tend to have a higher blood alcohol level than men of the same weight after drinking the same amount of alcohol. Therefore, with the same amount of intake, a woman's brain and other organs are exposed to more alcohol and more of its toxic byproducts.
As people get older, they usually have a higher fat-to-muscle ratio and less body water, so with the same amount of intake they may have more alcohol in the blood than younger people of the same weight.
What's in the drink
The water in beer or wine provides an extra buffer for the alcohol over a straight shot of liquor. That's why people tend to feel the effects of beer or wine a little less.
But the carbon dioxide in champagne or the soda in a mixed drink increases the rate of alcohol absorption, causing a more rapid effect.
How much food is in your stomach
If you eat a meal before drinking, alcohol absorption will be considerably slower than drinking on an empty stomach.
The medications you take
Alcohol reacts negatively with more than 150 medications, including sleeping pills, blood thinners and some antidepressant and anti-anxiety drugs, according to the National Clearinghouse for Alcohol and Drug Information. Because drinking alcohol with some medications can increase your intoxication level, be sure to ask your doctor or pharmacist if any of the medications you take can have this effect.
Your physical and emotional health
People who are fatigued or highly stressed often have a stronger reaction to moderate amounts of alcohol.
Alcohol and weight management
Alcohol contains significant calories, and drinking also may lead you to eat or overeat, especially when you are in a social setting, the NIAAA says. A 2005 study by the NIAAA found that women who drank the smallest amount of alcohol (one drink) with the greatest frequency (three to seven times a week) had a lower body mass index than women who drank less frequently but more at each drinking session.