The blood alcohol test measures only the amount
of alcohol in the blood at the time the sample is taken. It does not show how
long you have been drinking or whether you have an alcohol use
Highway patrol officers in most states now have devices
(toximeters) that measure the breath alcohol levels of drivers they think are
drunk. A person charged with drunken driving who does not think the breath
analysis is accurate may ask for a blood alcohol test.
that passes between drinking alcohol and collecting the blood or breath sample
affects test results. The body continues to break down alcohol at a steady rate
after drinking. So the amount of alcohol you drink can be estimated by knowing
how much alcohol is present in your blood or breath and how much time has
passed since you had a drink. In general, your body is able to break down about
one drink per hour.
A person who drinks alcohol and takes
certain medicines, such as
sedatives (tranquilizers), or narcotics, may feel more of the
effects of alcohol. Also, a person who uses other drugs, such as marijuana,
will feel the effects of both drugs more than if the drugs were used
alcohol self-test can estimate your blood alcohol concentration. The handheld
device to measure breath alcohol is similar to, though not as precise as, the
type of test used by police for suspected drunk drivers. The breath alcohol
self-test offers one piece of information to help you make a safe decision
about drinking and driving. The safest decision is always not to drive if you
have been drinking. To learn more, see the topic
Self-Test for Breath Alcohol.
Other Works Consulted
Chernecky CC, Berger BJ (2013). Laboratory Tests and Diagnostic Procedures, 6th ed. St. Louis: Saunders.
Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
Primary Medical Reviewer
E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer
R. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology