How a Medical Condition Could Change the Outcome of Your DUI Case in Chicago

If you’ve been arrested for DUI in Chicago and you have a medical condition that could have influenced the officer’s perception or affected your test results, it’s essential to understand that your health may form the foundation of a strong legal defense. Medical conditions are not only relevant to your wellbeing — they could also be the reason you were falsely accused of driving under the influence in the first place.

Even if you’ve already taken a breath test or admitted to having a drink, don’t assume that the case is open and shut. Medical explanations for certain symptoms or chemical readings are frequently overlooked by police and prosecutors, especially in busy cities like Chicago where officers are often quick to make judgments during traffic stops.

In Illinois, driving under the influence is taken seriously, but that doesn’t mean the charges are always accurate.

The Legal Framework: DUI in Illinois Under 625 ILCS 5/11-501

Illinois law defines DUI under 625 ILCS 5/11-501. According to the statute, it is illegal to operate a vehicle while:

• Under the influence of alcohol
• Impaired by drugs (legal or illegal)
• Having a blood alcohol concentration (BAC) of .08% or more
• Having any amount of a controlled substance in the body

In Chicago, most first-time DUIs are charged as a Class A misdemeanor, which can carry up to one year in jail and a fine up to $2,500. However, aggravating circumstances — like driving with a suspended license, having a passenger under 16, or causing serious injury — can elevate the offense to a felony DUI, also called Aggravated DUI, with penalties that include prison time and permanent loss of driving privileges.

But here’s the critical point: the law hinges on impairment or chemical results — and both can be heavily influenced by certain medical conditions.

When Medical Conditions Are Misread as Signs of Impairment

Many DUI arrests begin with a traffic stop for swerving, driving too slowly, or failing to signal. Once pulled over, officers will rely on visual cues and behavior to determine whether to proceed with a DUI investigation. But what if those behaviors are symptoms of a health problem?

Medical conditions frequently confused with intoxication include:

• Diabetes: Hypoglycemia (low blood sugar) or diabetic ketoacidosis can cause slurred speech, confusion, and a fruity breath odor.
• Epilepsy or Post-Seizure Behavior: People recovering from a seizure may appear disoriented and have trouble following instructions.
• Brain injuries or concussions: Symptoms can mimic alcohol-induced confusion or imbalance.
• Neurological disorders: Conditions like Parkinson’s disease or multiple sclerosis can affect balance, speech, and coordination.
• Acid reflux or GERD: These can cause falsely high breath test readings due to residual alcohol in the mouth.

Even officers with years on the job are not medically trained to distinguish these symptoms. A person could be completely sober and still fail field sobriety tests because of a legitimate condition.

Breath and Blood Tests Are Not Infallible in Illinois

In DUI cases, chemical testing plays a central role. Breath, blood, and urine tests are used to measure alcohol and drug levels. Under Illinois’ implied consent law (625 ILCS 5/11-501.1), drivers are expected to comply with chemical testing when lawfully arrested for DUI. Refusing a test results in an automatic license suspension, but even when tests are taken, their accuracy is not guaranteed.

Breathalyzers, in particular, are prone to errors when the person has:

• Acid reflux (alcohol vapor from the stomach can distort readings)
• Dental work that traps alcohol residue
• A diet high in acetone-producing substances (common in diabetics)
• A fever or medical infection that alters metabolic rates

Blood tests must also be administered correctly and processed according to chain-of-custody rules. If there’s any contamination or delay in analysis, results can be challenged. Your attorney can subpoena maintenance records for the testing device and the qualifications of the operator.

How DUI Charges Progress in Illinois

After arrest, the State initiates both a criminal case and a civil administrative suspension of your driver’s license. These are separate tracks, and you need to fight both to protect your rights.

The criminal process generally unfolds as follows:

• Initial Court Appearance: You’re informed of the charges and bail conditions.
• Pretrial Phase: This includes motions to suppress evidence, plea discussions, and reviewing discovery.
• Trial: If your case goes to trial, prosecutors must prove beyond a reasonable doubt that you were impaired or over the legal limit.

Your defense may hinge on introducing medical records, expert testimony, and cross-examination of the arresting officer. The earlier you retain legal counsel, the more time your attorney has to collect and present this crucial evidence.

Consequences of a DUI Conviction in Illinois

If you’re convicted, the penalties are significant. A first-time DUI conviction as a misdemeanor still results in:

• Up to 364 days in jail
• Fines up to $2,500
• A mandatory minimum of 12-month license suspension
• Court-mandated alcohol education or treatment
• A criminal record that cannot be sealed

If your offense is upgraded to a felony, you could be looking at years in prison and thousands in additional fees. Furthermore, your conviction will remain on your public record, affecting your employment, housing, professional licenses, and insurance premiums.

How an Attorney Can Help Build a Medical-Based DUI Defense

This is where strategic legal defense becomes essential. A qualified DUI defense attorney in Chicago will know how to:

• Obtain and review your medical history and prescriptions
• Work with doctors and medical experts to prepare reports
• Challenge the officer’s interpretation of your behavior
• File motions to suppress unreliable breath or field sobriety test results
• Advocate for reduced charges or dismissal

Often, when prosecutors see a legitimate medical explanation and a well-prepared defense, they become more open to negotiations or may drop the case entirely.

Why You Should Never Go to Court Without a Lawyer

It’s a mistake to assume that the judge will automatically take your word for it when you say you were having a medical episode. The criminal justice system is adversarial. The State has trained prosecutors, toxicologists, and officers on their side. You need someone standing up for you—someone who understands how medical conditions interact with DUI law in Illinois.

Even if you feel guilty or embarrassed, that doesn’t mean your case is lost. Everyone deserves a full defense, especially when your health played a role in what the officer observed. Your legal strategy should be proactive—not reactive. Waiting too long or trying to represent yourself only makes it harder to protect your license and avoid a permanent criminal record.

A Chicago DUI Defense Attorney Who Understands Your Health Matters

At The Law Offices of David L. Freidberg, we’ve represented countless clients in Cook County and the greater Chicago area who were arrested for DUI under misunderstood or exaggerated circumstances. We’ve helped clients with epilepsy, diabetes, PTSD, neurological disorders, and even severe anxiety who were wrongfully charged because of how they appeared during a traffic stop.

You deserve a defense that takes your full story into account — not just a breathalyzer result or an officer’s judgment call.

Call Now – The Law Offices of David L. Freidberg Is Ready to Help

If you’ve been charged with DUI in Chicago and have a medical condition that may have impacted your arrest or test results, call The Law Offices of David L. Freidberg for a free 24/7 consultation. 

If you were arrested in Chicago for DUI, protect your future by contacting The Law Offices of David L. Freidberg. We have decades of experience handling DUI cases in Illinois. Our firm is available 24/7 to provide the legal defense you deserve.

Contact us today at (312) 560-7100 or toll-free at (800) 803-1442 for a free consultation. We’re available 24/7 to serve clients throughout Illinois, Cook County, DuPage County, Will County, and Lake County.