If you’ve been charged with driving while intoxicated (DWI) in Texas, you may assume the evidence against you is straightforward. However, DWI cases are often more complex than they appear to be.
Many people are surprised to learn that certain medical conditions can affect field sobriety tests, breath tests and even blood test results. Understanding these issues is critical to protecting your rights.
Speaking of rights: Did you know you have the right to refuse a field sobriety test in Texas? Many people don’t. But don’t worry; even if you took the test, we know that medical conditions could affect the results and should be figured into your defense.
Here are five conditions that could affect your results in a field sobriety test.
1. Diabetes and Ketoacidosis
Diabetes, particularly when blood sugar is poorly controlled, can significantly interfere with breath alcohol testing. Diabetics may experience ketoacidosis, a condition that causes the body to produce acetone. Breath testing devices can mistake acetone for alcohol, leading to falsely elevated breath test readings.
Additionally, symptoms of low blood sugar, such as confusion, slurred speech, dizziness and unsteady balance, are often indistinguishable from signs of intoxication. A police officer may interpret a medical emergency as impairment.
2. Acid Reflux and GERD
People with gastroesophageal reflux disease (GERD) or chronic acid reflux are at higher risk for inaccurate breath test results. These conditions can cause alcohol vapors from the stomach to rise into the mouth and throat. When this happens, a breathalyzer may measure mouth alcohol instead of deep lung air, artificially inflating BAC results.
Texas DWI breath tests assume the alcohol measured comes from the lungs, not the stomach. A diagnosis of GERD can undermine that assumption.
3. Neurological and Balance Disorders
Field sobriety tests rely heavily on balance, coordination and eye movement. Medical conditions like these can make these tests unreliable:
- Vertigo
- Inner ear disorders
- Traumatic brain injuries
- Multiple sclerosis
- Parkinson’s disease
For example, the walk‑and‑turn and one‑leg stand tests assume a person has normal balance and mobility. Someone with a neurological condition may fail these tests even when they’re completely sober.
4. Eye Conditions and Nystagmus
One of the most common field sobriety tests is the Horizontal Gaze Nystagmus (HGN) test, which looks for involuntary eye jerking. While alcohol can cause nystagmus, so can eye disorders, head injuries, certain medications and neurological conditions.
When officers fail to rule out medical causes, HGN results may be misleading and improperly relied upon in court.
5. Prescription Medications
Many legally prescribed medications can mimic or exaggerate signs of intoxication. Medications that can cause drowsiness, slowed reaction time or coordination issues include:
- Sleep aids
- Anti‑anxiety medications
- Painkillers
- Muscle relaxants
- Antidepressants
Importantly, you can be charged with a DWI in Texas based on impairment from substances other than alcohol. Thus, a strong defense would not say that medication causes impairment; instead, it would highlight how medication could lead to an incorrect perception of impairment.
Why This Matters in a Texas DWI Case
DWI prosecutions often depend on assumptions. It’s assumed that test results are accurate and that certain observed behavior equals intoxication. Medical conditions challenge those assumptions.
When properly investigated, these challenges can raise reasonable doubt about the reliability of the state’s evidence. An experienced Texas DWI defense attorney can obtain medical records, consult experts and expose flaws in testing procedures.
If you have a condition that may have affected your DWI test, it could play a critical role in your defense. You’re not required to accept faulty science or misunderstood symptoms. The right legal DWI defense strategy can make all the difference.
Contact the Texas DWI Attorneys at Lee & Wood, GP
A drunk driving conviction carries stiff consequences in Texas. You need a strong defense. Contact our experienced team by calling 817-678-6771 or by filling out our contact form.