Blood Testing and Heavy Alcohol Use

March 3, 2021

Blood tests are used to measure the level of alcohol in someone’s blood. Most people are familiar with the breathalyzer, a test regularly used by the police when someone is suspected of drunk driving, but blood testing is more accurate.

When someone submits a blood test, the level of ethanol – the main ingredient in alcoholic drinks – is measured. As someone consumes alcohol, it slowly absorbs into the bloodstream and is processed by the liver. Generally, a healthy liver can process one alcoholic drink per hour. 

Will a Blood Test Show Heavy Alcohol Use?

The short answer is yes: blood testing can show heavy alcohol use. However, timing plays a significant role in the accuracy of blood alcohol testing. In a typical situation, blood alcohol tests are only accurate six to 12 hours after someone consumes their last beverage. 

Blood tests can help identify excessive alcohol use and possible liver damage. They may also be used to monitor changes in someone’s alcohol consumption during recovery.

How Blood Testing Detects Alcohol Abuse

Blood alcohol tests generally measure direct and indirect biomarkers. Most blood testing is conducted based on indirect biomarkers, which examine how the body and its organs are functioning. 

If the indirect biomarkers are outside normal ranges, it could be a result of heavy drinking. However, heavy drinking is not the only potential cause of abnormal indirect biomarkers. 

Direct biomarkers, on the other hand, are only produced when someone has consumed alcohol or increased their blood alcohol levels. Direct biomarker testing ensures the test gives an accurate picture of alcohol consumption, not affected by other factors. 

Different Types of Alcohol Blood Testing

Indirect alcohol abuse tests can include:

Carbohydrate-deficient Transferrin (CDT)

A CDT test is one of the more accurate indirect biomarkers. It has a 77 percent sensitivity for detecting chronic alcohol abuse. The normal ranges for this test are between zero and 1.6 percent. 

However, in individuals who drink heavily, the range can go as high as 10 percent. 

It is crucial to keep in mind that there are other factors that can contribute to a higher percentage of indirect biomarkers including:

  • medications
  • health
  • previous alcohol consumption
  • if the individual has liver disease 

Liver function test (LFT)

The primary biomarker in an LFT test is Gamma-glutamyl transferase (GGT). LFT is the second most reliable indirect marker, and studies show that GGT is a potential indicator of an individual’s alcohol use. 

Normal ranges for GGT are 10 to 71 iU/L in men. If someone has a result outside of this range, it can indicate alcohol abuse. Medications can increase levels of GGT, and these types of medications include:

  • warfarin 
  • antidepressants
  • barbiturates 
  • Cimetidine

However, an isolated rise in GGT is most commonly due to alcohol abuse or enzyme-inducing drugs. 

Full blood count (mean conspicuous volume – MCV)

The MCV test is a part of a full blood count (FBC) and is mainly used to identify recently ingested alcohol. This test looks at the average volume of red blood cells in the blood sample. 

While this test can provide some indication of possible alcohol abuse, it is the least accurate of all blood testing with a sensitivity rate of 44 percent. 

Direct Alcohol Abuse Testing

Phosphatidyl Ethanol (PEth)

PEth is a direct biomarker meaning it is only produced when someone consumes alcohol. With a sensitivity rate of over 99 percent, it is a far more dependable blood testing technique. 

Various levels of PEth can be used to indicate excessive alcohol consumption or binge drinking within the last 30 days and social drinking levels. 

What Happens During a Blood Alcohol Test?

Blood tests are typically gathered in a laboratory setting. This can include hospitals and separate lab testing sites. 

A healthcare professional will use a small needle to collect a sample of a blood sample from the vein in your arm. The whole process usually takes less than five minutes.

How Heavy Drinking Can Affect Your Health

Alcohol is a nervous system depressant, which works to slow down brain activity. Consuming excessive amounts of alcohol regularly can have numerous effects on someone’s overall health. 

The effects of alcohol can vary from person to person and depend on factors such as: 

  • how much you drank 
  • how quickly you drank it 
  • the amount of food you consumed before drinking 
  • your age 
  • your sex 
  • your race or ethnicity 
  • your physical condition 
  • family history of alcohol problems 

Health effects of heavy alcohol consumption can include but are not limited to the following: 

  • liver damage including, fatty liver and cirrhosis
  • stomach ulcers 
  • memory problems and brain damage 
  • nerve damage 
  • alcohol withdrawal symptoms 
  • depression and anxiety 
  • paranoia and hallucinations 
  • strokes 
  • heart attacks 

Recommended Drinking Limits

Men and women have different recommended drinking limits because their bodies process alcohol in different ways. Generally, men are larger and have more lean body mass than women, so they can handle more alcohol in one sitting, comparatively. 

Moderate drinking is no more than one standard drink a day for women and no more than two standard drinks for men. Standard drinks in the U.S. are defined as about 14 grams of pure alcohol, which may be found in: 

  • 12 ounces of beer (5 percent alcohol content) 
  • Five ounces of wine (12 percent alcohol content) 
  • 1.5 ounces of distilled spirits or liquor (40 percent alcohol content) 

What is Considered Excessive Drinking?

Excessive drinking includes binge drinking and heavy drinking. 

  • Binge drinking is when someone drinks so much at once that their blood alcohol concentration (BAC) level is 0.08 percent or more. In men, binge drinking usually happens after five or more drinks within a few hours. In women, it can happen after about four drinks within a few hours. 
  • Heavy drinking is when someone consumes 15 or more drinks in a week for men, and eight or more drinks in a week for women. 

While binge drinking can increase the risk of injuries, car crashes, and alcohol poisoning. Heavy drinking can also cause problems for individuals in their home and professional lives, but treatment can help. 

Finding Help for a Drinking Problem

Individuals looking to find help for their heavy drinking may want to consider an addiction treatment program. Elevate Addiction Services offers two locations in Northern California that provide alcohol abuse treatment. 

At Elevate, we believe in treating the whole person, not merely their symptoms. Alcohol abuse is a serious issue, and we are here to help. With a non-traditional approach to treatment, individuals who enroll at Elevate will experience a personally tailored treatment that fits them and their unique needs. 

We work hard to incorporate all aspects of a person, including their mental, emotional, physical, and spiritual needs. Elevate ensures that individuals have completed each phase of their recovery before moving on to the next stage. 

Individuals who struggle with heavy alcohol use will likely do best in an inpatient treatment program. Inpatient treatment requires individuals to live at the rehab facility, which can help people who need to experience a new environment to help them in their recovery.

To learn more about how Elevate Addiction Services, contact an addiction specialist today.

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This page does not provide medical advice
Written by Elevate Addiction Services | © 2021 Elevate Addiction Services | All Rights Reserved

Medically Reviewed by

Tim Sinnott, LMFT LAADC

December 29, 2020

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