What is a blood-alcohol test?

In general, law enforcement officials use three types of test to determine your blood-alcohol level: blood, urine, and breath tests. While blood tests measure the amount of alcohol in the blood system directly, urine and breath tests measure it, but then convert the results into blood-alcohol level using a mathematical formula. Though the tests are generally very accurate, they can be affects by the different rates at which people absorb alcohol, or the way the tests are conducted. It is a good idea, however, to get an independent analysis, if you are charged with a DUI. In many instances, police officers will take two samples, one for their own use, and one to be kept for independent testing, should you request such testing to occur.