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Testing for alcoholism

Laboratory tests can help diagnose a case of alcoholism but no single laboratory test or combination of tests has been shown to be ideal for screening or diagnosis. There are, however, some tests that are useful in evaluating patients:

  • Carbohydrate-deficient form of transferrin (CDT), a molecule involved in iron transport in blood. CDT is elevated in the blood of heavy drinkers but raised levels can also be found in a number of medical conditions. It is not useful as a screening test for alcohol abuse but may be useful in detecting those who have relapsed
  • Gamma-glutamyl transferase (GGT), a liver enzyme that is increased by heavy alcohol intake but also by other forms of liver disease
  • Mean corpuscular volume (MCV), a measure of the size of red blood cells, which is increased by prolonged heavy drinking
  • A blood alcohol (ethanol) level can be used to determine if a person has been drinking alcohol recently but does not diagnose alcoholism

The GGT result is more useful than the MCV result as a ‘red flag’ to raise the suspicion that the person is drinking too much. Both of these tests are relatively poor for screening or as diagnostic tests because conditions other than alcohol abuse or alcoholism can cause elevated levels.

Physical examination also may reveal signs suggestive of alcoholism, such as evidence of injuries, a visible network of enlarged veins just under the skin around the navel (called caput medusae), fluid in the abdomen (ascites), yellowish-tone to the skin, decreased testicular size in men and poor nutritional status.


Last Review Date: March 6, 2017