Can a Chicago DUI Lawyer Argue That My Medical Condition Was Misinterpreted as Impairment?

Understanding DUI Charges in Chicago and the Role of Misinterpreted Medical Conditions

In Chicago, DUI charges are aggressively prosecuted, often with severe consequences. But what happens when the signs police think indicate impairment—slurred speech, unsteady movements, bloodshot eyes—are actually caused by a medical condition? As a criminal defense attorney practicing for decades in Cook County and the surrounding areas, I’ve seen how fast assumptions can turn into formal charges. And unfortunately, these assumptions aren’t always rooted in science or medical knowledge.

Illinois DUI law, under 625 ILCS 5/11-501, criminalizes driving under the influence of alcohol, drugs, or any intoxicating compound. However, law enforcement officers rarely have medical training. This means they may interpret certain physical symptoms—like hypoglycemia from diabetes or neurological tremors—as proof of intoxication. These misinterpretations can lead to unjust arrests and life-altering consequences. In Illinois, a first-time DUI is typically a Class A misdemeanor, punishable by up to one year in jail and a fine of up to $2,500. Subsequent offenses or DUIs involving bodily harm, minors in the vehicle, or elevated blood alcohol content (BAC) can escalate to felonies.

The City of Chicago sees thousands of DUI arrests each year. Police officers may rely on field sobriety tests and perceived symptoms rather than solid science. Unfortunately, this opens the door to flawed arrests. If your medical condition mimics signs of intoxication, a strategic defense can make the difference between conviction and dismissal.

How DUI Investigations and Arrests Begin in Illinois

DUI cases in Illinois often begin with a traffic stop based on a moving violation, erratic driving, or even a DUI checkpoint. Once stopped, the officer begins looking for signs of impairment. If they believe they see slurred speech, glassy eyes, an odor of alcohol, or clumsy movements, they may proceed with field sobriety tests. These include the walk-and-turn test, the horizontal gaze nystagmus test, and the one-leg stand. But these tests are highly subjective and can be impacted by a host of physical conditions.

After roadside tests, officers may request a preliminary breath test. If the results suggest impairment—or if the officer simply believes you’re under the influence—you’ll likely be arrested and taken to the station for a chemical breath, blood, or urine test. Under 625 ILCS 5/11-501.1, Illinois has an implied consent law: refusing these tests can lead to a license suspension, even if you’re never convicted. If arrested, you’re fingerprinted, booked, and a formal complaint is filed.

From there, the case moves into the court system. You’ll face arraignment, pretrial hearings, and potentially a trial. Each stage is critical, especially if your medical condition played a role in the arrest. Without skilled legal representation, your defense may never be fully understood by the court.

Medical Conditions Commonly Misread as DUI Impairment

Several legitimate medical issues can cause symptoms that police mistake for DUI. For example, diabetes can cause slurred speech, confusion, and a fruity breath smell that mimics alcohol. Epilepsy or a seizure disorder may result in postictal confusion that looks like intoxication. Neurological conditions such as multiple sclerosis or Parkinson’s disease can cause coordination issues. Even anxiety or PTSD can cause erratic behavior or speech under stress.

In one recent case we handled, a client with a known seizure disorder was arrested for DUI after being pulled over for weaving. The officer misread the client’s delayed speech and slight tremor as intoxication. During pretrial motions, we introduced the client’s complete medical records and brought in a neurologist to testify. The prosecution dismissed the charges before trial.

These cases underscore the importance of a defense attorney who understands how to incorporate medical evidence into a DUI defense. We consult medical professionals, subpoena your health records, and challenge the subjective observations of law enforcement in court.

The Criminal Trial Process and How an Attorney Protects You

Once your DUI case enters the court system, the process unfolds through several phases. At arraignment, formal charges are read, and you enter a plea. Your attorney may begin immediately by filing pretrial motions, including motions to suppress evidence if the stop or arrest was unconstitutional under 725 ILCS 5/114-12.

During discovery, the prosecution is required to share evidence. This includes police reports, video footage, chemical test results, and body cam recordings. Your attorney will review these materials to identify weaknesses—especially if the arresting officer failed to consider your medical condition. For example, video footage might reveal slurred speech that is medically explained, not caused by alcohol.

If the case proceeds to trial, your attorney will present evidence that your symptoms were the result of a medical condition, not intoxication. This may involve testimony from medical experts, your treating physician, or pharmacologists. Trial-ready attorneys—especially those who routinely practice in Chicago’s courthouses—know how to challenge the credibility of officers and the reliability of testing procedures.

A seasoned trial lawyer doesn’t just argue; they dismantle. Prosecutors are less likely to proceed with flimsy evidence when they know your defense lawyer has a reputation for winning in court.

Evidence Law Enforcement Collects—and How to Challenge It

In DUI cases, police rely on three main types of evidence: observations, field sobriety test performance, and chemical test results. However, each of these can be flawed when a medical condition is present. Officers often write in their reports that a driver had slurred speech or trouble standing—but they fail to mention pre-existing conditions or medications.

Breathalyzer results can also be misleading. Some medical conditions can cause elevated acetone levels, which a breathalyzer might misread as alcohol. Certain medications or diets can affect breath chemistry. A good attorney will subpoena machine maintenance logs, calibration records, and the officer’s training history.

Field sobriety tests are voluntary in Illinois, yet most drivers don’t realize they can decline. The results of these tests are subjective and not scientifically reliable. We have consistently argued—and won—by demonstrating that poor performance was due to physical ailments, not intoxication.

Our case results speak for themselves. We’ve successfully challenged breathalyzer reliability, cross-examined police officers on inconsistencies, and introduced exonerating medical documentation in court.

Potential Legal Defenses Based on Medical Misinterpretation

Illinois law does not punish innocent drivers who suffer from medical conditions. But you need a defense attorney who can educate the court on why your symptoms were misread. Defenses may include:

• You were not impaired, and your behavior was the result of a diagnosed condition
• Your field sobriety test results were invalid due to physical limitations
• The breath test produced a false positive due to medication or a medical disorder
• The officer lacked probable cause for the stop or arrest

Defenses must be presented persuasively. It’s not enough to tell the court you have a medical issue—you need documentation, witnesses, and legal arguments that undermine the prosecution’s case.

What To Look for in a Criminal Defense Attorney—and What to Ask

If you’re facing DUI charges based on a misunderstanding of your health, don’t assume the truth will come out on its own. Prosecutors aren’t doctors. Judges aren’t pharmacists. You need a lawyer who understands how to translate your medical situation into a viable legal defense.

Ask potential attorneys:

• Have you handled DUI cases involving misdiagnosed medical conditions?
• Do you have access to medical experts or investigators?
• How often do you take cases to trial?
• What are the outcomes in cases similar to mine?

Not all attorneys are the same. Some focus only on quick plea deals. At The Law Offices of David L. Freidberg, we prepare every case for trial from day one. That pressure alone often gets results without ever setting foot in a courtroom.

Chicago DUI Defense FAQs

Can I be arrested for DUI in Chicago if I didn’t drink?
Yes. Illinois law allows for DUI charges based on perceived impairment from any cause—alcohol, drugs, or even fatigue. Unfortunately, officers sometimes confuse medical symptoms for signs of intoxication.

What happens if I refuse a breath or blood test in Chicago?
Under Illinois’ implied consent law, your driver’s license will be suspended for one year for a first refusal, and longer for subsequent refusals, even if you’re not convicted of DUI.

Will the court take my medical condition into account automatically?
No. If you don’t raise the issue and present evidence, the court may not even be aware you had a condition. Your attorney must proactively build that part of the defense.

Can I bring in my doctor as a witness?
Yes. In many cases, we subpoena treating physicians or bring in independent medical experts to explain your symptoms to the court or jury.

Will my medical history be used against me?
Not typically. If you waive certain privacy rights to support your defense, your records can help you, not harm you. A skilled attorney will manage what gets presented strategically.

How long does a DUI case last in Cook County?
It depends, but many cases last several months due to court scheduling, evidence review, and motion hearings. Your attorney will keep you informed at every stage.

Can I still be charged with DUI if I passed the breath test?
Yes. A DUI charge can be based on drugs, medical impairment, or officer observations alone—even with a 0.00 BAC. That’s why a medical-based defense is crucial.

Is field sobriety testing mandatory in Illinois?
No. You have the right to refuse field sobriety tests, though most people don’t know that. These tests are not reliable, especially for individuals with health conditions.

Can I lose my job over a DUI arrest?
Possibly. Even before a conviction, some employers will act on an arrest. A conviction may also affect professional licenses. Quick legal intervention is key.

Does it help if this is my first DUI?
Absolutely. First-time offenders may be eligible for court supervision or other alternatives—but only if your attorney pushes for them and presents a strong case.

Why You Need an Attorney—and Why to Choose David L. Freidberg

If you’ve been charged with DUI due to a misinterpreted medical issue, trying to defend yourself is a serious mistake. Judges expect defense lawyers to challenge medical misunderstandings with facts, evidence, and legal arguments. Without that, you may be convicted for something that wasn’t your fault.

At The Law Offices of David L. Freidberg, we’ve successfully defended countless clients facing DUI charges that stemmed from medical confusion. We know how to obtain, analyze, and present medical evidence. We take the time to understand your health history, hire expert witnesses when needed, and fight to protect your record, license, and reputation.

We serve clients throughout Chicago, Cook County, DuPage County, Will County, and Lake County. Our aggressive and trial-ready approach has helped people just like you get their charges dismissed or reduced.

Why The Law Offices of David L. Freidberg Is the Right Choice

The Law Offices of David L. Freidberg has decades of experience defending DUI cases in Chicago and across Cook, DuPage, Will, and Lake Counties. We prepare every case as if it will go to trial, giving our clients the upper hand from the very first appearance. Whether your goal is to get charges dismissed or negotiate a favorable plea, our courtroom readiness makes a real difference.

We have successfully defended clients in some of the toughest DUI courts in Illinois. When you hire us, you get a strategic defense tailored to your case and a relentless advocate fighting for your future.

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.