GERD, Acid Reflux, and Heartburn:
Medical DUI Defenses

Medical conditions such as gastroesophageal reflux disease (GERD), acid reflux, hiatal hernia and heartburn can lead to false results on a DUI breath test.

Let's say you were pulled over for DUI. You had had a drink or maybe two—but nowhere near enough alcohol to make you feel intoxicated.

But the breathalyzer results show that you had a blood alcohol concentration (BAC) over the legal limit, even though that seems impossible to you. So you are charged with Vehicle Code 23152(b) VC driving with a BAC of 0.08% or above.

The problem here might be a medical condition like GERD, acid reflux or a hiatal hernia. These conditions cause stomach acid to flow back into the esophagus (the “food pipe” that connects the stomach with the throat).1

If there is any alcohol in your stomach, this can create the phenomenon called “mouth alcohol.” This in turn can lead a DUI breath test to measure a higher BAC than you actually had.

Hundreds of GERD, acid reflux and heartburn sufferers are wrongly arrested for DUI each year. If you think you might be one of them, you don't have to suffer alone. Understanding how GERD/acid reflux/heartburn can affect breathalyzer results can be the key to a successful DUI defense strategy.

To help you understand how GERD, reflux, heartburn and hiatal hernia can “trick” California DUI breath testing devices, our DUI defense attorneys will answer the following frequently asked questions:

Is it possible for a DUI breath test result to be wrong?

DUI defense attorneys who understand the science behind DUI breath testing know that it is entirely possible for a breathalyzer result to be wrong—especially when medical conditions like GERD/acid reflux are involved.

Unlike DUI blood tests, DUI breath tests can only approximate the amount of alcohol in your blood. They do this more accurately if the air that is blown into a breathalyzer is “deep lung air.”2

A problem can occur when there is unabsorbed alcohol in the mouth. This “mouth alcohol” can fool a breathalyzer by combining with the alcohol from deep lung air.3 And mouth alcohol is particularly common in people who suffer from GERD or acid reflux.

Prosecutors claim that modern DUI breath testing equipment is sensitive enough to distinguish mouth alcohol from deep lung air.4 However, tests have shown that this simply isn't always so.

How can GERD/acid reflux lead to an incorrect BAC reading?

Many people experience acid reflux and heartburn—its major symptom--from time to time. When reflux becomes chronic, it is known as gastroesophageal reflux disease (GERD).5

In normal digestion, the lower esophageal sphincter (LES) opens to allow food to pass into the stomach.  After eating, the LES closes to prevent stomach contents from flowing back into the esophagus.

If the LES doesn't close all the way or opens too often, stomach acid and contents can flow back up into your esophagus—and even all the way to your mouth.6

And if your stomach contents include alcohol, then you will end up with alcohol in your mouth—and that alcohol will show up on the results of a DUI breath test.

What is a “hiatal hernia,” and can it affect my DUI breath test?

A “hiatal hernia” is when part of your stomach pushes up through your diaphragm. It can allow food and stomach acid to pass back into your stomach—creating the same conditions as acid reflux/GERD.7

A hiatal hernia can definitely affect your DUI breathalyzer results because it, like GERD, can lead to alcohol in your stomach being pushed into your mouth. The DUI breath testing equipment will then mistake that alcohol for the alcohol deep in your lungs that reflects your BAC.

How do I know if GERD or heartburn affected my breathalyzer test?

GERD is an under-diagnosed condition. If left untreated, it can lead to esophageal erosion and even cancer. Your doctor can perform tests to determine if you suffer from GERD.

But even if you don't have GERD, you may still experience occasional acid reflux and heartburn—a much less severe and more common condition.

Infrequent heartburn is more common than GERD and can also cause inaccurate DUI breath test results.

A good California DUI defense attorney will conduct a thorough interview to see if acid reflux or heartburn might have caused a falsely high BAC reading on your DUI breath test.

If it did, this can form the basis for a successful DUI defense based around casting doubt on your breathalyzer results.

With the help of a DUI expert witness, your DUI defense attorney can explain the science of DUI testing and the impact of acid reflux and heartburn to the prosecutor--and, if necessary, to the judge and jury.

The prosecutor says that GERD can't have affected my breathalyzer results because the police followed Title 17. Is this true?

Most mouth alcohol--including that caused by acid reflux, GERD, and heartburn--evaporates within 15 minutes. This is why Title 17 of the California Code of Regulations requires that law enforcement continually observe you for 15 minutes before administering a DUI breath test.8

The idea is that, by continuously observing you, the test operator can visually ensure that during this time no alcohol is added to your mouth from:

  • ingested sources (such as alcoholic drinks or mouthwashes containing alcohol), or
  • regurgitated sources (such as vomiting or belching).

However, as Victorville DUI defense attorney Michael Scafiddi9 explains:

"Regurgitation caused by GERD, acid reflux, or heartburn isn't always apparent to an onlooker. So even if the officer followed Title 17 by observing you for 15 minutes to make sure you didn't burp, belch, or regurgitate, he or she may simply have missed the signs of regurgitation related to acid reflux.”

In other words, adherence to Title 17 does not mean that GERD is not a valid defense to your DUI charges.

Call us for help…

GERD california dui legal defense
Call us for help

For more information about the role of GERD, acid reflux, heartburn or a hiatic hernia in your DUI defense, or to discuss your case confidentially with one of our DUI defense attorneys, please don't hesitate to contact us at Shouse Law Group. Our California criminal law offices are located in and around Los Angeles, Orange County, San Diego, Riverside, San Bernardino, Ventura, San Jose, Oakland, the San Francisco Bay area, and several nearby cities.

Legal References:

  1. See Mayo Clinic, GERD: Definition.
  2. People v. McNeal (2009), 46 Cal.4th 1183, 1191. ("When a subject blows into a breath-testing machine, the device measures the amount of alcohol vapor expelled into alveolar spaces deep in the lungs [in theory, that is--in practice GERD, acid reflux/heartburn, or a hiatal hernia can prevent this from happening].")
  3. American Medical Association's Committee on Medical Problems -- Manual for Chemical Tests for Intoxication (1959). ("True reactions with alcohol in expired breath from sources other than the alveolar air (eructation, regurgitation, vomiting) [which can be caused by GERD/acid reflux] will, of course, vitiate the breath alcohol results...") 
  4. Jeanne Swartz, Breath Testing for Prosecutors: Targeting Hardcore Impaired Drivers, American Prosecutors Research Institute.
  5. Mayo Clinic, Is Acid Reflux the Same as GERD?
  6. WebMD, What Is Acid Reflux Disease?
  7. Mayo Clinic, Hiatal Hernia: Definition.
  8. Title 17 California Code of Regulations, Section 1219.3.
  9. Victorville DUI defense attorney Michael Scafiddi uses his experience as a former Ontario police officer to defend clients accused of DUI in the Inland Empire, including Hemet, Riverside, San Bernardino, and Palm Springs. He is familiar with the range of DUI defenses, including medical defenses such as GERD/acid reflux.

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