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.
Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.