A variety of tests exist to determine the concentration of alcohol in the body and past alcohol use. Alcohol tests utilize a wide range of methods and can measure alcohol concentrations in most body fluids. Most of these tests focus on determining the amount of alcohol currently in your body or blood. Additional tests attempt to determine patterns of chronic or past alcohol use or abuse.
Alcohol Levels
Alcohol levels in the blood will be elevated following alcohol consumption. Low levels between 0.02% and 0.03% produce a relaxing feeling in most people. As levels increase to 0.05 to 0.10% you may have decreased reaction time and impaired judgment. Levels above 0.08% define legally intoxicated in most states.
Blood Alcohol Test
Blood alcohol tests directly measure the amount of alcohol in the blood and are therefore the most accurate alcohol test. Blood alcohol tests commonly exist as a part of more comprehensive toxicology screens used to detect levels of legal and illegal drugs, making them the test of choice in emergency situations. Depending on the level of intoxication and clearance rate of the individual, blood alcohol tests can detect alcohol for three to 10 hours after drinking.
Breath Alcohol Test
Breath alcohol tests estimate the blood alcohol concentration by measuring the amount of alcohol in your breath. Many types of breath alcohol tests exist, using different technologies. Breath alcohol tests are non-invasive, easy to use and inexpensive, making this the most commonly used type of alcohol test.
Urine alcohol test
Urine alcohol tests are another widely used type. They are capable of detecting alcohol over a relatively longer time period than many other measures and can determine alcohol consumption within the past few days. While urine alcohol tests remain a commonly used and trusted method of detection, susceptibilities to alterations such as dilution or substitution may interfere with their use in some situations.
Saliva Alcohol Test
Saliva alcohol content provides a close approximation of blood alcohol levels. While no nationally accepted cutoffs yet exist for saliva alcohol levels, testing by this method has found increasing support due to the non-invasive nature and relatively low cost of the test.
Testing for Chronic Alcohol Use
Hair tests provide a good indicator of alcohol use over the preceding months or even years. Hair alcohol tests rely on chemical changes in the growing hair produced when alcohol is present. Additional blood tests used for assessment of chronic alcohol use include blood levels of the liver enzyme gamma-glutamyl transferase and carbohydrate-deficient form of transferrin, folate deficiency and changes in red blood cell structure.
