Driving under the influence (DUI) is a serious offense with potentially life-altering consequences. However, not every DUI charge is based on accurate science. One surprising medical condition that can influence breath test results is Gastroesophageal Reflux Disease (GERD), along with related conditions like acid reflux and heartburn.
This article explores how GERD can lead to false positives on breathalyzer tests, what the science says, how this can affect a DUI defense, and what legal options may be available if you suffer from this condition.
What Is GERD?
Gastroesophageal Reflux Disease (GERD) is a chronic condition where stomach acid frequently flows back into the esophagus — the tube connecting your mouth and stomach. This acid reflux can cause:
-
Heartburn
-
Regurgitation
-
Difficulty swallowing
-
Chest pain
-
A sour taste in the mouth
For many people, GERD can flare up after eating, lying down, or consuming acidic or spicy foods. In more severe cases, stomach contents can make their way as far as the throat or mouth, especially during episodes of belching or vomiting.
How DUI Breath Tests Work
To understand the link between GERD and false DUI results, it’s essential to know how breathalyzers work.
Breathalyzer Basics
Police typically use a breathalyzer to estimate Blood Alcohol Concentration (BAC). These devices measure the amount of ethanol (alcohol) in the breath, under the assumption that it reflects the level of alcohol in the blood.
There are two main types of tests:
-
Preliminary Alcohol Screening (PAS) – Usually done at the roadside with a handheld device.
-
Evidentiary Breath Test (EBT) – A more accurate test, typically conducted at the police station.
Breathalyzers are calibrated to measure alcohol deep in the lungs (alveolar air), which is assumed to represent the alcohol in your bloodstream. However, this assumption becomes problematic when alcohol is present in the mouth or upper digestive tract, as is often the case with GERD.
How GERD Can Cause a False Positive on a Breathalyzer
1. Mouth Alcohol Contamination
In people with GERD or acid reflux, gastric contents — including alcohol — can regurgitate into the esophagus or mouth. When this happens, the breathalyzer may detect mouth alcohol rather than deep lung air. This can produce a falsely elevated BAC reading.
Even trace amounts of alcohol in the mouth can significantly skew test results. For example:
-
Alcohol from belching or vomiting can linger in the mouth.
-
The residual alcohol mixes with your breath and can be mistaken for blood alcohol.
-
This is not a true reflection of intoxication — it’s contamination from the upper GI tract.
2. Timing and Symptoms Matter
GERD symptoms may not be constant but may worsen under certain conditions:
-
After eating or drinking (especially alcohol or carbonated beverages)
-
When lying down or bending over
-
During periods of stress
If you were pulled over soon after eating or drinking, or were experiencing reflux symptoms during the breath test, the chance of a false positive significantly increases.
Legal Standards and Safeguards: The Observation Period
To reduce the risk of mouth alcohol interference, in California a 15-minute observation period is required before a breath test is administered. During this time, the suspect must not:
-
Eat or drink
-
Vomit or burp
-
Chew gum or tobacco
However, if an officer fails to properly observe this waiting period or does not recognize signs of reflux, the test may be compromised — providing an opening for a strong medical DUI defense.
How to Use GERD as a DUI Defense
If you suffer from GERD and were charged with DUI based on a breath test, you may be able to challenge the results.
Steps to Take:
1. Document Your Condition
-
Obtain medical records confirming a diagnosis of GERD, acid reflux, or similar disorders.
-
Keep track of prescriptions, treatments, and symptoms (especially if they occurred during or around the time of arrest).
2. Hire an Experienced DUI Attorney
A knowledgeable attorney can:
-
Subpoena the breath test records and verify whether proper procedures were followed.
-
Consult with toxicology or medical experts.
-
Argue that your GERD caused mouth alcohol contamination, leading to a false BAC reading.
3. Challenge the Test’s Reliability
If there’s no evidence of an observation period or the officer ignored visible symptoms (e.g., burping, nausea), the test may be inadmissible or subject to scrutiny in court.
Other Medical Conditions That May Affect Breathalyzer Accuracy
GERD isn’t the only condition that can interfere with DUI tests. Other relevant conditions include:
-
Hiatal hernia – Often accompanies GERD and increases reflux risk.
-
Diabetes (Ketoacidosis) – Can produce acetone, a compound that some breathalyzers mistake for alcohol.
-
Liver disease – Can alter alcohol metabolism and test results.
-
Asthma inhalers – Some contain alcohol-based propellants.
All of these may serve as part of a broader medical DUI defense strategy.
Can You Still Be Convicted If You Have GERD?
Yes — but only if the prosecution can prove your BAC accurately reflects impairment.
If a breath test is thrown out or questioned due to GERD, the state may still rely on:
-
Field sobriety test results
-
Officer testimony
-
Driving behavior
-
Blood test results (which are not affected by mouth alcohol)
However, if the case depends heavily on the breath test, challenging its validity due to GERD can be a powerful defense.
Final Thoughts: Know Your Rights and Medical Defenses
Being charged with DUI is frightening, but medical conditions like GERD can provide legitimate explanations for elevated BAC readings that don’t reflect actual intoxication. Breathalyzers are not foolproof, and failing to consider health factors may result in unjust charges or convictions.
If you believe your breath test was influenced by GERD, acid reflux, or a similar issue, speak to an experienced DUI attorney immediately. With the right documentation and expert testimony, your condition could play a pivotal role in your defense.
If you’ve been charged with DUI and believe GERD, acid reflux, or another medical condition may have affected your breath test, you don’t have to face the system alone.
At Southwest Legal, we understand the science behind DUI defenses — and we know how to fight for your rights. Our experienced legal team has successfully challenged flawed breath test results and helped clients avoid unjust convictions based on medical conditions. Don’t let a medical condition lead to a criminal record. Call us today.
Frequently Asked Questions (FAQs)
Q: Can a breathalyzer really be wrong because of acid reflux?
A: Yes. Reflux can bring alcohol from the stomach into the mouth, contaminating breath samples and causing falsely high BAC readings.
Q: Do all states recognize GERD as a DUI defense?
A: Most allow medical defenses if they can be supported by credible evidence. The success varies depending on state laws and the specifics of the case.
Q: Is a blood test more reliable than a breath test if I have GERD?
A: Generally, yes. Blood tests measure alcohol directly in the bloodstream and are not affected by mouth alcohol.
