Taking a blood alcohol test checks the amount of alcohol in the body, according to WebMD. The test determines the alcohol level in the blood, especially when an individual appears intoxicated and shows alcohol intoxication symptoms, such as confusion, obscure thinking, unsteadiness in walking or unusual driving.
In some cases, authorities order a blood alcohol test to check the presence of alcohol in the blood of people who are prohibited from drinking alcoholic beverages, such as underage individuals and those who are taking an alcohol treatment program, states WebMD. The test involves wrapping an elastic band around the upper arm to obstruct blood flow, enlarging the veins below the band for easy insertion of a needle.
A health care professional cleans the site of injection, inserts the needle into the vein, and connects a tube to the needle for collecting blood, explains WebMD. After gathering a sufficient amount of blood, the nurse removes the band, puts a cotton ball on the needle site, adds pressure on the area, and wraps a bandage.
Alcohol is easy to measure minutes following alcohol consumption as the blood absorbs it quickly, notes WebMD. The blood contains the highest alcohol level an hour after consuming alcohol. Small amounts of alcohol affects the body noticeably. When consumed in considerable amounts, alcohol serves as a sedative and weakens the central nervous system.