Alcohol Breath Tests: How Do They Work?

You've likely read a lot about sobriety checkpoints. News accounts usually showcase officers at a specified location stopping cars as they come through, administering a breathalyzer test to ensure people aren't driving under the influence.

But how do those tests really work? I was exploring that for a discussion recently, and came across a great graphic on the NIDA for teens website. The National Institute for Drug Abuse (NIDA) does a lot of work on the drug issue, providing great information on the effects and consequences of using.

The graphic shows how alcohol breath tests work. It goes something like this:

  1. Alcohol that you drink moves from your mouth to your stomach.
  2. It gets absorbed into the blood -which has already been exposed to oxygen in the lungs - in the stomach and small intestine.
  3. the alcohol is carried throughout your body in the blood. including the brain and lungs.
  4. Alcohol is transferred to the lungs and exhaled through the breath.

Within minutes of having a drink, a person's BAC - blood alcohol concentration - can be measured. And it's at it's highest about an hour after drinking.

Lots of things affect BAC, like a person's weight, age, sex, and how much they've had to drink.

Take time to get familiar with how alcohol works in the human body, and learn how it can affect you - not just when tested by police, but also how it affects growth and brain development. The more you know ... well, the more you know.