Driving under the influence (DUI) is a serious offense, and breathalyzer tests are a common tool used by law enforcement to assess a driver’s level of intoxication. However, what many people don’t know is that certain medical conditions—particularly diabetes—can interfere with the accuracy of these tests. In some cases, individuals with diabetes may face false positives, potentially leading to wrongful DUI charges.
This article explains how diabetes and a related complication called diabetic ketoacidosis (DKA) can impact DUI breathalyzer results, how the technology works, and what individuals with diabetes need to know to protect themselves.
How Breathalyzer Tests Work
Before diving into how diabetes affects breathalyzer readings, it’s important to understand how the devices function.
Breathalyzers estimate blood alcohol concentration (BAC) by measuring the amount of ethyl alcohol (ethanol) in a person’s breath. When someone consumes alcohol, it enters the bloodstream, and a portion of it is exhaled through the lungs. A breathalyzer captures a sample of that exhaled air and uses infrared spectroscopy, fuel cell sensors, or semiconductor sensors to detect the ethanol levels and estimate the BAC.
The legal BAC limit for drivers in most U.S. states is 0.08%. If a driver’s breath sample reads at or above this level, they can be arrested and charged with DUI—even if they appear relatively sober.
Diabetes and DUI: The Key Connection
1. The Role of Ketones in Diabetic Metabolism
People with diabetes, especially Type 1, can experience a condition known as diabetic ketoacidosis (DKA). This occurs when the body cannot use glucose properly due to a lack of insulin, prompting it to burn fat for energy instead. A byproduct of this fat metabolism is the production of ketones.
Some ketones—specifically acetone—can be exhaled through the lungs. Interestingly, acetone has a chemical structure similar to isopropanol and ethanol, the types of alcohol detected by breathalyzers. As a result, certain types of breathalyzers may misidentify acetone as ethanol, leading to false-positive readings for alcohol consumption.
2. Hypoglycemia and Behavior Confusion
In addition to chemical interference, hypoglycemia (low blood sugar), which is common among diabetics, can cause confusion, slurred speech, poor coordination, and other symptoms that mimic intoxication. To an untrained observer—or even a police officer—these symptoms may be mistaken for signs of alcohol impairment, prompting a breathalyzer test in the first place.
Scientific Studies Supporting the Claim
Several studies and forensic experts have confirmed that elevated ketone levels can impact breathalyzer readings:
A study published in the Journal of Analytical Toxicology noted that acetone concentrations in diabetic patients can reach levels high enough to trigger false positives on certain breathalyzers, especially older models using semiconductor sensors.
Research in Clinical Chemistry concluded that acetone can be detected in exhaled breath and may interfere with electrochemical detection methods in DUI breath tests.
Real-life legal cases have documented instances where diabetic individuals were falsely arrested for DUI, only to be later cleared when medical records confirmed their condition.
Types of Breathalyzers
Not all breathalyzers are equally susceptible to interference from diabetic ketosis. Here’s how the different types respond:
Semiconductor-based breathalyzers
Often used in personal or preliminary police testing.
Highly sensitive to compounds like acetone.
More likely to produce false positives in diabetics.
Fuel cell breathalyzers
More commonly used by law enforcement.
Less sensitive to acetone but not completely immune.
Infrared spectroscopy breathalyzers (Evidential Breath Testers or EBTs)
Typically used at police stations.
Can differentiate between ethanol and other chemicals more accurately.
Least likely to be fooled by diabetic ketones.
Legal Implications for Diabetics
A false DUI charge can have devastating consequences: license suspension, fines, legal fees, and even jail time. For diabetic individuals, being misidentified as intoxicated due to breathalyzer error is not just frustrating—it can be life-altering.
What You Should Do if You’re Diabetic and Pulled Over:
Inform the officer of your medical condition immediately.
Request a blood test in addition to the breathalyzer. Blood tests are far more accurate and are not affected by acetone.
Carry medical documentation indicating that you have diabetes and are prone to ketosis or hypoglycemia.
Avoid self-incrimination; politely decline to answer questions about alcohol consumption without a lawyer.
Speak to a DUI attorney familiar with medical defenses, particularly involving diabetes and breathalyzer reliability.
Your Rights and Protections
In many jurisdictions, you have the right to challenge DUI charges based on medical conditions. Courts have accepted diabetes-related defenses when there’s credible evidence that:
The defendant has a documented diagnosis of diabetes.
DKA was present at the time of the arrest.
A breathalyzer model known for interference was used.
Blood tests showed no alcohol in the system.
It’s important to note that refusing a breathalyzer test may lead to immediate penalties, including license suspension, depending on your state laws. Always consult with legal counsel if you’re unsure about your rights during a traffic stop.
Conclusion
Diabetes, particularly when it leads to ketoacidosis, can significantly interfere with DUI breathalyzer results. The presence of acetone in the breath, combined with behavioral symptoms of hypoglycemia, can mimic alcohol intoxication in both appearance and chemical testing.
If you or someone you know has diabetes, understanding the relationship between your health and DUI law is crucial. Always carry medical identification, request confirmatory blood tests, and know your rights. With increased awareness and accurate information, we can help ensure that breathalyzer technology doesn’t unintentionally penalize people for medical conditions.
Have you or a loved one been charged with DUI due to a medical condition like diabetes? Don’t face the legal system alone. Contact Southwest Legal today for a free consultation. Our experienced DUI defense attorneys understand how health conditions can impact breathalyzer results—and we’re here to fight for your rights.
Frequently Asked Questions (FAQs)
Can a diabetic fail a breathalyzer test without drinking alcohol?
Yes. Due to diabetic ketoacidosis, the body can produce acetone, which may trigger a false positive on some breathalyzer models.
Will a blood test detect alcohol if I have diabetes but didn’t drink?
No. Blood tests are more accurate and specific to ethanol, so if you haven’t consumed alcohol, your blood alcohol level should read zero.
Should I tell the officer I have diabetes during a DUI stop?
Yes, always disclose medical conditions that may affect behavior or breath test results. It may prevent misunderstandings and be helpful in court if needed.
Can diabetes be used as a legal defense in a DUI case?
Yes, if it’s shown that a medical condition caused a false positive or misinterpreted behavior. Medical records and expert testimony can support this defense.
