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Urine and blood tests

There are reliable tests for the actual use of alcohol, one common test being that of blood alcohol content (BAC). These tests do not differentiate people with alcohol use disorders from people without; however, long-term heavy drinking does have a few recognizable effects on the body, including:

With regard to alcoholism, BAC is useful to judge alcohol tolerance, which in turn is a sign of alcoholism. Electrolyte and acid-base abnormalities including hypokalemia, hypomagnesemia, hyponatremia, hyperuricemia, metabolic acidosis, and respiratory alkalosis are common in people with alcohol use disorders.

However, none of these blood tests for biological markers is as sensitive as screening questionnaires.