Typically, a set of screening surveys is given to an individual to determine if he or she is alcoholic. Laboratory tests are usually used to detect chronic or relapse drinking in individuals that deny abusing alcohol, but are showing symptoms of alcoholism. So, what blood tests show alcoholism?
Alcoholism Screening Survey
Before any laboratory tests are done, individuals are usually given a questionnaire to fill out to determine if they suffer from alcoholism. The most common survey is the 25 question Michigan Alcohol Screening Test (MAST). There are shorter versions of the MAST, but each version usually asks the individual how many days he or she has consumed alcohol heavily in the past year. Doctors verify the results of the survey with blood tests.
Below is information on what blood tests show alcoholism.
Gamma-glutamyl Transferase (GGT) Test
One of the tests used by doctors to determine if an individual is drinking excessively is the Gamma-glutamyl Transferase (GGT) test. This is a blood test that measures the level of gamma-glutamyl transferase, a liver enzyme. This enzyme is produced at a higher rate in individuals that drink alcohol heavily. In fact, this enzyme will be elevated in about 75% of chronic drinkers.1
The GGT test can screen for chronic alcohol abuse, or it can be used to monitor an individual that is being treated for alcoholism. The GGT test can also monitor the progression of alcoholic hepatitis.
Mean Corpuscular Volume
The Mean Corpuscular Volume (MCV) is a measure of the size of the red blood cells. The blood test is typically taken from a vein with a needle. Individuals that have abused alcohol by drinking heavily will have a MCV that is higher than normal. The MCV is part of a broader test called the Complete Blood Count (CBC) test.
The Liver Panel consists of several tests that measure how well the liver is functioning. It is usually ordered when an individual has symptoms of liver dysfunction. Heavy drinkers will have some form of liver damage that is detectable with a liver test. For example, an individual with alcoholic hepatitis will have a normal or increased bilirubin level, twice the amount of aspartate aminotransferase (AST) than alanine aminotransferase (ALT), and a normal or slight increase in alkaline phosphatase (ALP).
Individuals that have been drinking heavily for several years may develop cirrhosis of the liver. It is diagnosed with several tests on the liver panel. The bilirubin level is slightly increased in late stages of the disease, while the AST level is higher than the ALT level. ALP is normal or slightly increased, and the albumin level is decreased. The prothrombin time (PT), which is a measure of how well the blood is clotting, is usually increased in individuals with cirrhosis.2
Magnesium and Folate Tests
When asked, "what blood tests show alcoholism", the magnesium and folate test are probably mentioned last. Insufficient dietary intake due to alcoholism can reduce the level of magnesium, while the level of vitamin B12 and folate also drop. In the case of folate, the body absorbs less of it, and the kidneys excrete more of it in individuals that abuse alcohol.
1. "GGT: The Test" Lab Tests Online. 20 Sept. 2010. 17 Oct. 2010 - http://www.labtestsonline.org/understanding/analytes/ggt/test.html
2. "Liver Panel: The Test" Lab Tests Online. 23 June 2010. 17 Oct. 2010 - http://www.labtestsonline.org/understanding/analytes/liver_panel/test.html
3. "Alcoholism" Lab Tests Online. 18 June 2010. 17 Oct. 2010 - http://www.labtestsonline.org/understanding/conditions/alcoholism-2.html
4. Dugdale, David C "RBC Indices" Medline Plus. 9 Feb. 2010. 17 Oct. 2010 - http://www.nlm.nih.gov/medlineplus/ency/article/003648.htm