Lab Tests For Alcoholism Are:
Complete Blood Count (CBC)
The blood count of alcoholics shows reductions in haemoglobin, white blood cells, red blood cells and haematocrit in the blood count of alcoholics .
Blood count test results indicative of alcoholism are:
Carbohydrate Deficient Transferrin (CDT)
A CDT reading over 10% indicates extreme alcohol abuse [normal range 0.1-1.6%].
If there is alcohol consumption over 5 units a day, transferrin is unable to take iron molecules from the intestine to areas of the body that need iron, creating a higher reading .
Mean Corpuscular Volume (MCV)
This test analyses the average volume of red blood cells in a specimen of blood .
Ethyl Glucoronide & Ethyl Sulphate
Heavy alcohol consumption is indicated by readings over 1,000 ng/mL, with levels between 500-1,000 ng/mL indicating heavy drinking in the previous 3 days, light drinking in the past 24 hours or intense exposure to alcohol in the last 24 hours .
Liver Function Test (LFT)
Liver function tests evaluate different proteins and enzymes in the blood to check for a depletion in levels indicative of alcoholism:
Gamma GT (Glutyl amino transferase)
A reading above or below 10-71 iU/l is a potential indicator of alcohol consumption .
A PEth reading of over 210.48 ug/l indicates excessive or binge drinking in the last 30 days [normal range <20ug/l].
A reading above 35 ug/l indicates some alcohol consumption, whereas a reading between 35-210.48 ug/l suggests social drinking .
Alcoholism Blood Test Biomarker Summary
Alcoholism Levels ( + Short Term)
Long Term Alcoholism
0.1 - 1.6%
10% or over 
80 - 100 fl 
Over 100 fl 
Ethyl Glucoronide & Ethyl Sulphate
Less than 500 ng/mL
Over 500 fl ng/mL
Over 1000 fl ng/mL 
Below 10 or over 71 iU/l
Less than 20 ug/l
Over 35 ug/l
Over 210.48 ug/l
Over 13.5 seconds
135-317 billion for women and 157-371 billion
Less than 135 billion for women and 157 for men
Lower Platelet count
Lower Platelet Count
As findings in MCV or GGT tests may be influenced by vitamin deficiencies or medication, more specific markers such as PEth tests must be used to confirm abnormalities suggesting alcohol use .
In GGT tests, a change in levels appears after 70 drinks per week for several weeks and returns to normal after 2-6 weeks, whereas CDT test changes appear after 60 drinks per week for at least two weeks and return to normal after 2-4 weeks, creating varying results .
In CDT tests, women have higher levels than men regardless of previous drinking, giving the tests greater scope for inaccuracy .
Full Blood Test vs Liver Function Test
Full Blood Test
Liver Function Test
Measures red blood cells, white blood cells and platelets?
Measures enzymes and proteins?
Testing for anemia and blood clotting?
Monitoring responses to treatment?
Testing for liver infections?
Medically unexplained symptoms?
Family history of live disease?
Medication that can harm liver?
Short Term vs Chronic Alcoholism Biomarkers
Ethyl Glucuronide and ethyl sulphate are indicative of alcohol ingestion up to to 36 hours in the blood and 5 days in urine .
Serum albumin, bilirubin and prothrombin time tests indicate long term alcoholism, and evaluate the liver for cirrhosis and chronic liver disease .
What Alcohol Blood Testing Is Not
As blood alcohol tests are typically at their most accurate 6-12 hours after the last drink, social drinkers, stress drinkers and binge drinkers are behaviours that are harder to identify through blood tests .
Alcohol blood tests cannot track historic alcohol abuse, or how long an alcoholic has been abstinent for, before the most recent alcohol use .
Interpreting Blood Alcoholism Test Results
Clinicians look for physical signs of alcoholism alongside test results:
The CDT test has an accuracy rate of 77%, the MCV test being 44% and the PEth test being the most accurate at 99% .
Clinicians complete a psychological evaluation and evaluate drinking habits to decide whether symptoms correlate to alcoholism .
The patient must be both physically and psychologically dependent on alcohol to be classed as having an alcohol use disorder.
A follow up blood test would be ordered if:
Drinking around 1 litre of water may lower the concentration of substances in the body and lead to a false negative .
It is still necessary to drink water, as dehydration causes the possibility of a false positive, but not over 1 litre .
Warfarin means the blood is less likely to clot, creating the potential for a false negative in a PT test .
Other drugs that may cause a false negative include:
Food And Drink
Yeast with sugar, apple juice, non-alcoholic wine or beer and ripe bananas have been known to cause false positive readings due to alcohol content, meaning they should be avoided before any blood test, particularly those that require fasting beforehand .
Dehydration causes increased levels of haemoglobin and haematocrit, meaning drinking water avoids a false positive result .
Products Containing Alcohol
Mouthwash, hand sanitisers, hairspray and cosmetics contain alcohol, meaning regular use may lead to a positive test result and should be avoided before a blood test .
Paracetamol causes an increase in bilirubin, creating a false positive, particularly in LFTs.
Clinicians should be aware of the amount paracetamol taken before a test .
Smoking causes increased haematocrit, haemoglobin and mean corpuscular volume, that may be mistaken for a positive alcohol consumption reading .
Nicotine and cotinine, the chemicals in cigarettes, leave the blood stream after 10 days, so a clinician will need to be made aware if they are performing a blood test on a smoker .
Follow Up / Further Testing
Follow up tests may look for: