5 Things You Should Know Before Your Polygraph Examination

Whether you're taking a polygraph for pre-employment screening, a legal matter, or personal reasons, proper preparation can help ensure accurate results. Here's what you need to know from a certified examiner with nearly two decades of experience.

1. Get Adequate Sleep the Night Before

This is perhaps the most important preparation tip. Sleep deprivation affects your physiological responses in ways that can complicate the examination. Aim for at least 6-8 hours of quality sleep the night before your test.

When you're well-rested, your baseline physiological readings are more stable, making it easier to detect meaningful changes during the relevant questions. Fatigue can cause erratic readings that may lead to inconclusive results.

2. Eat Normally and Stay Hydrated

Don't skip meals before your examination, but don't overeat either. A normal, balanced meal a few hours before your appointment is ideal. Low blood sugar can affect your concentration and physiological responses.

3. Take Your Regular Medications

If you take prescription medications, continue taking them as prescribed. Do NOT skip doses thinking it will help with the test—it won't, and it could actually cause problems.

However, you must disclose all medications during the pre-test interview. This allows the examiner to account for any potential effects on your physiological responses. Some medications, particularly those affecting heart rate or blood pressure, may need to be noted in the final report.

4. Understand That Nervousness Is Normal

Almost everyone is nervous before a polygraph examination—this is completely normal and expected. The good news? General nervousness does NOT cause you to "fail" the test.

The polygraph measures specific physiological responses to specific questions, not your overall anxiety level. A skilled examiner establishes your baseline readings while accounting for normal nervousness. The comparison is between your responses to different types of questions, not against some "calm" standard.

5. Be Completely Honest

This might seem obvious, but it's worth emphasizing: the best way to pass a polygraph is to tell the truth. The examination is designed to detect deception, and attempting to manipulate your responses typically backfires.

During the pre-test interview, you'll have the opportunity to discuss any concerns about the questions. If there's something in your past that worries you, it's better to disclose it upfront than to try to hide it during the test. Many issues that seem significant to you may not be disqualifying factors.

What to Bring

• • Valid government-issued photo ID
• • List of current medications
• • Any paperwork provided by the requesting party
• • Reading glasses if you need them

The Bottom Line

A polygraph examination isn't something to fear if you're being truthful. Proper preparation—good sleep, normal eating, taking your medications, and being honest—sets you up for the most accurate results possible. The examination process is straightforward, and a professional examiner will explain everything before you begin.