The breath alcohol test measures the amount of alcohol in the blood by testing exhaled air. The test is performed by blowing into a breath machine 15 minutes after alcohol consumption. The test determines how much alcohol it takes to raise the blood-alcohol level to a dangerous level.
Review Date 4/4/2018
Updated by: Jacob L. Heller, MD, MHA, Emergency Medicine, Emeritus, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.