How Can Diabetes Affect Your DUI Breath Test?

Legally reviewed by:
Rubin, Glickman, Steinberg & Gifford P.C.
June 30, 2024

How Can Diabetes Affect Your DUI Breath Test Breath tests or breathalyzers in Pennsylvania drunk driving cases are increasingly common despite their shortcomings. While a blood test is more precise in determining a driver’s blood alcohol content (BAC), a breath test is far more convenient and can lead to false positives. Ketones produced during diabetic ketosis can be mistaken for alcohol by breathalyzer devices, leading to inaccurately high BAC readings and potential DUI charges. It is possible to administer a blood test anywhere, but it requires considerable preparation. In Pennsylvania, breath tests to measure a driver’s BAC are performed according to the basic principle known as Henry’s Law.

How Does Henry’s Law Affect Breath Tests in Pennsylvania? 

According to Henry’s Law, whenever a liquid containing a volatile substance, like alcohol, contacts air in a closed container, like through a breath test, the concentration of alcohol in the air and the liquid are equivalent. Breath testing devices gauge alcohol concentration in a person’s breath and multiply it by a predefined coefficient to calculate a person’s approximate BAC. That is how breath testing depends on scientific theories and measurements.

Since breath tests assess alcohol concentration in a person’s body through their breath, it is essential to establish whether any medical conditions could negatively affect the results. Further, it’s critical to determine whether a medical condition, like diabetes, might cause a driver’s breath test result to show that they are intoxicated when, indeed, their disease was the cause for the higher BAC reading. Ketones produced during ketosis in diabetic individuals can be mistaken for ethyl alcohol by breath testing devices. This can lead to falsely high blood alcohol concentration readings and result in inaccurate DUI charges.

How Does Blood Sugar in Diabetes Play a Role in DUI Defense?

If you have diabetes and have been arrested for driving under the influence, a skilled DUI defense attorney may potentially use your condition as part of your defense. When someone has diabetes, their body does not effectively use or produce enough insulin, which is a hormone that converts food into energy. High blood sugar levels can also affect breathalyzer readings, leading to potential false positive results.

Low blood sugar, also known as hypoglycemia, can impact the accuracy of breath tests in DUI cases. The presence of acetones in the breath of diabetics suffering from hypoglycemia may be mistaken for ethyl alcohol by breath testing devices, leading to inaccurate results.

There are two types of diabetes individuals may be diagnosed:

  • Type 1 Diabetes: Typically diagnosed in adolescents or children, this type of diabetes affects about 5-10% of the population and causes the body to stop producing insulin.
  • Type 2 Diabetes: Representing the vast majority of the population who suffer from diabetes, this type either causes the body not to produce enough insulin or the body’s cells ignore the insulin already produced.

When you provide a breath sample, the machine measures more than just the alcohol concentration. Breath tests in Pennsylvania use infrared spectrometry, which also picks up acetone, a byproduct of a metabolic state called Ketoacidosis, which can negatively impact breath test results.

Individuals with Type 1 Diabetes often experience diabetic Ketoacidosis, which can cause their breath to smell fruity. Should a police officer stop them while driving and smell their breath, they may confuse this smell with alcohol and suspect they are drunk driving.

How Does Acetone Affect False Positive Breath Testing in Pennsylvania?

Acetone is naturally occurring and is usually present in the body after the breakdown of fat. This can lead to a false positive reading on a breathalyzer, as elevated glucose levels in the body can cause an overestimation of alcohol concentration in the analysis. Individuals with Type 1 Diabetes usually have higher acetone levels in their breath, which can be falsely identified as ethanol. Studies in ketone body excretion, such as the one published in the Journal of Biological Chemistry in 1931, highlight how diabetes can affect breath test results. As a result, the breath test may show they are driving with a BAC over the legal limit, even if they have not consumed alcohol at all.

How Can an Experienced DUI Lawyer in Montgomery County Help?

If the breath test does not measure the level of acetone in a person’s breath, the prosecution won’t differentiate ethanol from acetone. That can create reasonable doubt about the breath test’s findings or cause the judge to rule that the results are inadmissible in DUI cases.

It is crucial for a law enforcement officer to understand medical conditions like diabetes when conducting breathalyzer testing. A lack of understanding can lead to false arrests and potentially harmful repercussions for individuals with diabetes.

If your DUI defense lawyer is going to argue a defense based on diabetes, you must provide them with the following pieces of information:

  • When you were diagnosed with diabetes
  • Whether you have Type 1 or Type 2 Diabetes
  • The primary care physician who treats your diabetes
  • Blood glucose testing records, when applicable
  • Details of your eating habits
  • The time of your last insulin injection before being stopped by police
  • What time you last had a meal or snack before being pulled over

Your lawyer cannot assert a defense strategy founded on diabetes without this information. Further, in Pennsylvania, defense lawyers are required to provide this information to the prosecution per the rules of criminal procedure.

Talk to Seasoned DUI Defense Lawyers in Montgomery County for Free Today

If you’re facing DUI charges in Montgomery County, Pennsylvania, and have diabetes, get in touch with the skilled DUI defense lawyers at Rubin, Glickman, Steinberg & Gifford, P.C. Symptoms of diabetes, such as slurred speech, can be mistaken for alcohol impairment. In the event diabetes may be asserted as a defense to a DUI charge, we are prepared to walk you through each step, ask the right questions, and build a powerful defense to your charges. Ketones produced during diabetic ketosis can lead to inaccurate breathalyzer readings by fooling the device into mistaking them for ethyl alcohol, the type of alcohol found in alcoholic drinks. This can result in false accusations of DUI even when the individual has not been drinking at all.

For over 65 years, our legal professionals have advocated for clients accused of drunk driving throughout Montgomery County, Bucks County, and Southeastern Pennsylvania. Speak to one of our experienced DUI defense lawyers about your situation over a free consultation by completing a contact form or call 215-822-7575 today.


Legally reviewed by:
Rubin, Glickman, Steinberg & Gifford P.C.
Pennsylvania Attorney's
June 30, 2024
Established in 1952 by Irwin S. Rubin, Rubin, Glickman, Steinberg & Gifford P.C. boasts over 65 years of experience serving clients throughout Pennsylvania. Renowned for its commitment to ethical representation, the firm has garnered prestigious accolades, including being named the "Best Law Firm" for its outstanding legal defense work by U.S. News & World Report. Their team of seasoned attorneys, recognized as Pennsylvania Super Lawyers and Rising Stars, brings unparalleled expertise to a wide range of legal matters, ensuring exceptional representation for individuals, families, businesses, and organizations.