How Long Does Alcohol Stay in the Body?

Alcohol is detectable in blood for about 10 hours after consumption. After that, it is usually not detected.

When a person takes alcohol, it slowly enters into its blood stream. While in blood, alcohol is slowly excreted out in sweat, breath and urine. It may be detected by Breathalyzers or urine analyzers during this phase.

Where is Alcohol Present in Your Body After Consumption?

After you take alcohol, it goes into your stomach and intestines to get absorbed gradually. This is how it enters the blood.

It circulates with blood to reach all the tissue of the body. This chemical is able to cross most barriers. It easily enters the brain tissue, crosses the placental barrier to reach the fetus in pregnant women.

Alcohol is a toxic chemical and has detrimental effects on the brain, liver cells, kidney and other body tissues. So, our liver metabolizes it as quickly as possible to avoid its detrimental effects.

It normally takes 10 to 12 hours to remove an average heavy intake of alcohol from the blood. During these hours, it may be detected in blood.

Blood Alcohol

Blood alcohol is measured and detected as Blood Alcohol Content (BAC). However, taking blood sample and seeing for alcohol in it would be cumbersome. This is not usually done. Detecting in breath or urine sample is common.

Rate of Metabolism

Alcohol burns off at the rate of .016 BAC per hour. This means, your liver metabolizes around 1 standard drink each hour.

The rate of metabolism of alcohol is almost the same in all individuals, however, age, height, weight and sex do affect the BAC (blood alcohol content) of a person.

Factors Affecting Absorption of Alcohol in the Blood and its Metabolism

1) Whether alcohol was taken alone or with food is an important factor that will decide its absorption.

When taken on an empty stomach, alcohol gets absorbed very quickly. If food is taken along, its absorption is retarded.

The more bulky or fibrous the food, more slow is alcohol absorption.

2) Obese people absorb this chemical at a slower rate.

3) Females tend to have a higher BAC than male, when same amount of alcohol was taken by both.

Also, all damages caused by alcohol occur more in females than in males.

Common Methods of Alcohol Detection

Common methods of detection include

  • Detecting alcohol in breath
  • Detecting alcohol in urine

Both these methods are actually detecting blood alcohol. Alcohol present in blood goes to all organs, including the kidneys. Kidneys filter it out and show it in urine. Similarly, blood alcohol reaches the lungs. From there, it is exhaled out during expiration.

Detecting Alcohol in Breath

Breathalyzers are used to detect and measure blood alcohol content. They are the most commonly used way to detect alcohol. Used more during field detection as by traffic police on duty. This method is easy to use.

Using a Breathalyzer

The person to be checked is asked to breath into the breathalyzer. If ethanol (drinking alcohol), is present in his breath, a mild current is generated and the instrument shows its presence .The amount of current is directly proportional to the amount of alcohol present in his breath.

How Does a Breathalyzer Work?

Breathalyzer basically has two electrodes, a positive one and a negative one. When ethanol enters the breathyzer, it is oxidized to acetic acid at one electrode. At the other electrode, a reduction reaction takes place where oxygen is reduced to produce water.

This reaction generates a current, whose amount corresponds to the amount of ethanol in breath.

Getting False Positives With Breathalyzers

Breathalzers are easy to use, but not very reliable. False positive may occur, as in thefollowing examples.

  • Acetone produces the same results like ethanol. So, if you have acetone in your breath and you’re made to breath into a Breathalyzer, you breath may show positive for ethanol. This may happen in diabetic patients, in people who have not eaten for a long time or in those who are dieting.
  • People suffering for acid reflux problem may falsely show positive.
  • You may also be tested positive if you’ve recently used any mouth wash containing alcohol.
  • Rubbing an alcohol based hand sanitizer on your hands or after a dental procedure performed in your oral cavity.

Detecting Alcohol in Urine

This is done by ETG testing.

Alcohol is broken down in the liver into its metabolites, one of them being ethyl glucuronide.

In ETG testing, the presence of this metabolite is searched in the urine sample. Urine may show ETG after 3 to 4 hours of alcohol consumption. For this reason, this test is also called 80 hours test.

This test is widely used, as in people on probation, professionals not allowed to take alcohol on duty, and at many other places.

Medical Advice (Q&As) on “Alcohol Detection in the Body

  1. Roxy

    If I drink 30 ounces of beer on Sunday night, will the alcohol in my urine be detected in a test sent to the lab. My test is the following Wednesday. They are testing for alcohol use.

    1. Buddy M.D. Post author

      It is unlikely to be detected.

      However, if you are a regular user of this chemical, it is difficult to comment.

  2. Toni

    I had 44 oz of beer on Sunday night. Last sip at 10 pm. Will the metabolite show up Wednesday afternoon? Lots of water with lemon till then.

          1. Buddy M.D. Post author

            ETG testing detects Ethyl Glucuronide, which is a metabolite of ethanol (alcohol). While ethanol is detectable for 10 hours, its metabolite can be detected for about 3 to 4 days!

        1. Buddy M.D. Post author

          The rate of elimination also depends upon your rate of metabolism. Unless your rate of metabolism is too slow, it should not take so long to eliminate this chemical.


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