Polygraph when you are anxious, in pain or short of sleep: should you go and what to say

Should you go for a polygraph test if you have not slept, something hurts or you are on medication? The short answer: sometimes it is better to postpone, because testing a person in poor condition raises the risk of a wrong conclusion. Below is what the rules of the American Polygraph Association (APA) say about it.

The topic is not new, but people ask about it all the time: “I’m very nervous”, “my back hurts”, “I’ve just come off a night shift”, “I take blood pressure tablets”. General advice on preparing is in the article “How to pass a polygraph”. This one deals only with specific conditions: when the test goes ahead, when it is postponed and what to tell the polygraph examiner before it starts.

Nervousness: why it does not “fail” the test

Everyone is nervous, and that is expected. The American Polygraph Association (APA) explains it this way in its frequently asked questions: anxiety does raise heart rate and blood pressure, but during the test that raised level becomes the person’s normal baseline. The polygraph examiner is not looking at how high the pulse is, but at changes relative to that baseline in response to specific questions. According to the APA, there is no evidence that anxiety alone causes a truthful person to “fail” the test.

So “I’m nervous” is not a reason to refuse. It is a reason to say so out loud at the start of the meeting.

Tiredness and a sleepless night

The APA distinguishes between two things. Ordinary daytime tiredness does not affect the result. Extreme fatigue can be grounds for postponing the examination.

The reason: a classic examination lasts 1.5–3 hours, and for all that time you have to listen carefully to the questions and sit still while the recording is made. That is hard for someone who is falling asleep on their feet – the recording comes out poor, and the polygraph examiner cannot reach a confident conclusion.

Pain and acute illness

The APA model policy on examinee suitability for testing (2021) explicitly lists severe pain, serious injury and acute illness that interfere with the examination among the conditions in which testing is not carried out or is deferred. Separately, the APA notes that a person with a temporary illness can be booked for another date once they have recovered.

Chronic conditions are a different matter. Under the same policy, a stable diagnosis does not in itself rule out a test: the polygraph examiner records it in the report, adapts the procedure if necessary and presents the conclusion with an appropriate caveat. There are also purely technical obstacles. Skin that is too dry or too moist, or calluses on the fingers, make recording difficult. The APA adds to the list conditions in which the sensors cannot be attached or the person cannot sit still for several minutes at a time.

Medication, sedatives, energy drinks

The most common mistake is to stop taking your own tablets before the test or, on the contrary, to take a sedative “to stop the shaking”. The APA advises the opposite: take medication prescribed by your doctor as usual and give the polygraph examiner a list of it. According to the association, prescription medication for the most part does not spoil the recording; some drugs make an inconclusive result more likely, but medication acts equally on all the test questions, and no increase in the number of wrong conclusions because of it has been recorded.

Taking a sedative or an energy drink deliberately in order to influence the test, however, is a bad idea. Such attempts usually show up as early as the practice tests: if there are no reactions, the polygraph examiner will postpone the examination.

Alcohol and hangovers

The APA considers a person with noticeable signs of intoxication – from alcohol or drugs – unsuitable for testing. With a hangover it is better not to take the risk and to rearrange the meeting: the day will be lost both for you and for the client.

Pregnancy

The APA does not prohibit testing pregnant women, but advises the polygraph examiner to rely on the doctor’s opinion. The examiner may ask for a note confirming that the pregnancy is proceeding without complications, and may defer the test if the pregnancy is complicated or high-risk.

When the test is postponed

I do not carry out an examination if the person is in acute pain, exhausted, has gone more than 24 hours without sleep, is intoxicated by alcohol or drugs, or is in the late stages of pregnancy. From my own practice: I ask about sleep, medication and how the person is feeling before the sensors are attached. Postponing a test is a normal working situation, not a sign that the person is hiding something.

If the problem is that sitting through a long procedure is difficult, shorter formats are sometimes suitable – EyeDetect (up to 45 minutes, in Lviv only) or the online VerifEye test taken on a smartphone. No method gives 100%, and intoxication or an acute condition is a reason to put off any of them.

What to tell the polygraph examiner before the start

The pre-test interview takes up most of the meeting, and that is the right place for it. Say:

• how long you slept last night and whether you have come straight from a night shift;
• which medication you take regularly and what you have taken today, including sedatives and painkillers;
• whether you drank alcohol the day before;
• what hurts right now and whether you will be able to sit still;
• any chronic diagnoses – heart, blood pressure, diabetes, asthma – and pregnancy;
• if you start to feel unwell during the test itself – straight away, without waiting for the end.

Employers would do well to build a spare day into the schedule: an examination in an unsuitable condition does not save money, it produces a questionable conclusion. A reminder that an examination is possible only with voluntary written consent, and the person has the right to ask for another date. This is not medical or legal advice: consult your own doctor about medication and diagnoses.

FAQ

Should you own up to your “little sins”?

This question is often asked on forums the day before an examination. It is worth telling what relates to the subject of the test. As the APA describes it, the questions are built on what the person says during the interview, the final wording is agreed with them before the recording, and there are no surprise questions in modern techniques. If something about a question bothers you, say so before the test, not after.

Can you have coffee or a sedative before the test?

Coffee – yes, but no later than 2–3 hours before the test. The APA advises not changing your normal routine and only avoiding excessive stimulants and unnecessary over-the-counter medicines, because they make the session drag on. Do not take a sedative “for courage”. If your doctor has prescribed it, take it as directed and say so.

What happens if you keep quiet about feeling unwell?

Most likely the recording will be poor and the result inconclusive – you will have to come back again. If you are unsure whether to go, write or call in advance.