Can Medical Conditions Like GERD or Diabetes Cause a False DUI in California?

Imagine this nightmare scenario: You are driving home from work in Nevada County. You are tired, perhaps a bit stressed, but you certainly haven’t been drinking to excess—or maybe you haven’t touched a drop of alcohol at all. Suddenly, red and blue lights flash in your rearview mirror.

During the stop, you blow into a breathalyzer, confident you will pass. But when the officer looks at the device, their demeanor changes. You are handcuffed and arrested for driving under the influence (DUI) because the machine says you are over the 0.08% legal limit.

How is this possible?

For many drivers in California, the answer lies not in a bottle of wine, but in their own medical history. Conditions like Gastroesophageal Reflux Disease (GERD), diabetes, and even strict diets can trick breathalyzers into generating “false positive” results. At The Win Law Firm, led by former prosecutor Kenny Nguyen, we know that science is not infallible. Machines make mistakes, and medical realities can mimic criminal behavior.

If you are facing DUI charges and suffer from a chronic health issue, your medical records might be the key to your freedom.

How Do California Breathalyzers Actually Work?

To understand how a medical condition can ruin your driving record, you first need to understand the flawed science behind the breathalyzer.

Contrary to popular belief, a breathalyzer does not measure the alcohol in your blood. It measures the alcohol in your breath and uses a mathematical conversion (called a partition ratio) to estimate how much is in your bloodstream. This process relies on Henry’s Law, which presumes that the alcohol evaporating from your lungs is directly proportional to the alcohol in your blood.

However, for this reading to be accurate, the device must capture “deep lung air” (alveolar air)—the air from the bottom of your lungs that is closest to your blood supply.

The machine assumes that any alcohol it detects is coming from your deep lung air. It does not know if the alcohol is actually coming from your stomach, your throat, or even chemical compounds your own body produced. This inability to distinguish the source of the alcohol is where medical defenses come into play.

Can GERD Really Cause a False DUI?

Yes, and it is one of the most valid scientific defenses in DUI law. Gastroesophageal Reflux Disease (GERD), commonly known as acid reflux or chronic heartburn, affects millions of Americans. It occurs when the lower esophageal sphincter (the muscle that closes your stomach off from your throat) is weak or relaxes inappropriately.

What Is “Mouth Alcohol”?

In a DUI context, “mouth alcohol” is the enemy of accuracy. If you have raw alcohol in your mouth—from recently sipping a drink, using mouthwash, or regurgitation—the breathalyzer will read that alcohol directly.

Because the sensor is expecting diluted air from your lungs, a blast of pure alcohol vapor from your mouth can cause the machine to register a BAC that is artificially high.

The GERD Connection

If you suffer from GERD, your stomach contents—including acids and undigested alcohol—can flow back up into your esophagus and mouth. This can happen silently; you might not even feel a full “burp” or heartburn.

• The Scenario: You had one glass of wine with dinner two hours ago. Legally, you should be well under the limit.
• The Reflux: Due to GERD, a small amount of alcohol vapor regurgitates into your throat just before you blow into the device.
• The Result: The breathalyzer detects this concentrated mouth alcohol and reads a 0.12% BAC, even though your actual blood alcohol is 0.03%.

The Importance of the 15-Minute Observation Rule

California’s Title 17 regulations mandate that an officer must observe you continuously for 15 minutes before administering a breath test. This is specifically to ensure you do not vomit, eat, drink, or regurgitate.

However, officers often look away, do paperwork, or simply fail to notice a “silent” reflux event. If we can prove you suffer from GERD and the officer failed to conduct a proper observation, the breath test results may be deemed unreliable in court.

How Does Diabetes Trigger False High BAC Readings?

Diabetes is another medical condition that can lead to wrongful DUI convictions, but through a completely different chemical mechanism. This defense applies particularly to Type 1 diabetics, though it can affect Type 2 diabetics as well.

The Problem of Ketosis

When a person with diabetes has low insulin levels, their body cannot use glucose (blood sugar) for energy. Instead, the body begins to burn stored fat for fuel. This metabolic process produces waste products called ketones.

One specific type of ketone produced is acetone. Acetone is expelled from the body through urine and—crucially—breath.

Acetone vs. Ethanol

Here is the problem: Acetone is chemically similar to isopropyl alcohol. Many older or less sophisticated breathalyzers use infrared spectroscopy that struggles to distinguish between ethanol (drinking alcohol) and acetone (molecularly similar).

If you are a diabetic in a state of ketosis, your breath may be saturated with acetone. A breathalyzer may read this acetone as ethyl alcohol, reporting a high BAC when you haven’t been drinking at all.

Hypoglycemia Mimicking Drunkenness

Beyond the breath test, diabetes can cause you to fail Field Sobriety Tests (FSTs). If you experience hypoglycemia (low blood sugar), your brain is starved of fuel. The symptoms of hypoglycemia are nearly identical to intoxication:

• Slurred speech
• Confusion and disorientation
• Sweating and flushed face
• Stumbling or poor balance
• Shakiness

A police officer seeing these signs will almost always assume alcohol is the cause, leading to an arrest before you even take a breath test.

Are Low-Carb or Keto Diets Risky for DUI Stops?

Surprisingly, you do not need to be diabetic to suffer from the “acetone effect.” The popularity of high-protein, low-carbohydrate diets (like the Keto diet, Paleo, or Atkins) has created a new class of innocent DUI defendants.

The entire goal of the Keto diet is to force the body into a state of ketosis—burning fat instead of carbs. Just like in a diabetic, this intentional ketosis produces high levels of acetone on the breath.

If you are strictly adhering to a Keto diet and are pulled over, you could register a false positive on a breathalyzer. This is essentially “dietary innocent ingestion.” You are not intoxicated; you are just metabolically burning fat.

Do Other Medical Conditions Affect Field Sobriety Tests?

Breathalyzers aren’t the only hurdle; Field Sobriety Tests (FSTs) are notoriously subjective and difficult, even for healthy individuals. Officers use tests like the “Walk-and-Turn” or “One-Leg Stand” to judge your physical coordination.

However, these tests assume you have a “normal” baseline of agility and balance. Many medical conditions make passing these tests impossible, regardless of sobriety:

• Neurological Disorders: Conditions like Multiple Sclerosis (MS), Parkinson’s disease, or epilepsy can cause tremors, rigid muscles, and unsteadiness.
• Inner Ear Issues: Vertigo or labyrinthitis directly impacts your equilibrium. An officer might claim you “stumbled,” taking it as a sign of guilt, when it was actually a medical symptom.
• Skeletal/Muscular Injuries: Previous back injuries, knee surgeries, or even arthritis can prevent you from walking a straight line heel-to-toe without swaying.

Officers rarely ask detailed questions about your medical history on the side of the road. They simply mark down “failed test” and move toward an arrest.

How Can a Former Prosecutor Help Win Your Case?

When you are fighting a DUI charge based on a medical defense, you are not just fighting the facts; you are fighting the system. The District Attorney will likely argue that the machine is accurate and that your condition is just an excuse.

This is where The Win Law Firm offers a distinct advantage.

Kenny Nguyen is a former prosecutor. He knows exactly how the other side builds their case. He knows:

• How prosecutors try to discredit medical experts.
• The specific maintenance logs required for breathalyzers (and how to find gaps in them).
• How to cross-examine arresting officers to reveal they ignored Title 17 observation periods.

We don’t just tell the court you have GERD or diabetes; we build a timeline. We use medical records, expert testimony from toxicologists, and the officer’s own body cam footage to show that your “intoxication” was actually a medical event.

Conclusion

A DUI arrest does not automatically mean a conviction. If you suffer from GERD, diabetes, or other physical ailments, the “evidence” against you might be scientifically flawed. You should not be punished for your medical history.

At The Win Law Firm, we specialize in peeling back the layers of a DUI arrest to find the truth. If your body tricked the breathalyzer, we will make sure the court knows it.

Don’t let a medical condition define your criminal record.

Contact The Win Law Firm Today

Ready to fight for your future? Contact The Win Law Firm today to schedule your free consultation. We serve Nevada County, Placer County, and the surrounding areas.

Disclaimer: This blog post is for informational purposes only and does not constitute legal advice. Always consult a licensed attorney for guidance specific to your case.

Frequently Asked Questions (FAQ)

Can I get a DUI dismissed if I have GERD?

It is possible. If we can prove that your GERD caused “mouth alcohol” to contaminate the breathalyzer sample, and that the officer failed to follow the 15-minute observation rule, the breath test evidence can be suppressed. Without reliable BAC evidence, the prosecution’s case often falls apart.

Why did I fail the breath test if I haven’t been drinking?

If you have diabetes or are on a Keto diet, your body may be producing acetones. Some breathalyzers confuse these acetones with ethyl alcohol. Alternatively, if you have acid reflux, alcohol vapor from your stomach may have regurgitated into your mouth, causing a falsely high reading.

Do I have to tell the officer about my medical condition?

You are not legally required to disclose your full medical history on the roadside, and anything you say can be used against you. However, if you are experiencing a medical emergency (like hypoglycemia), you should alert them so you can receive medical aid. It is generally best to remain polite, exercise your right to remain silent regarding the drinking, and save the medical defense for your attorney to present in court.

Does high blood pressure affect DUI results?

High blood pressure itself typically does not skew a breathalyzer result. However, the anxiety of being pulled over can spike blood pressure, causing a flushed face and rapid speech—symptoms officers often mistake for intoxication.

How do I prove my medical condition caused the false positive?

We use a combination of evidence: your medical records (showing a history of GERD/diabetes), expert witness testimony (toxicologists who explain the science), and sometimes independent blood re-testing. We also analyze the breathalyzer’s calibration records to see if it was functioning correctly.