017 3249 5941 [email protected]

A polygraph, also widely known as a lie detector, is an instrument designed to measure and record physiological responses to questions, with the aim of determining truthfulness or deception. These devices are often employed in law enforcement, intelligence agencies, and various sensitive job positions where honesty is paramount. However, the interpretation of polygraph results is not as straightforward as it seems, with various factors potentially influencing the outcome – medical conditions being a significant one.

Many medical conditions, and sometimes the medications used to treat them, can alter the physiological responses that polygraphs rely upon. If a person has any of these conditions, it’s crucial to notify the polygraph examiner beforehand, to avoid potential misinterpretation of results. Here are some of the medical conditions that may affect polygraph results:

Anxiety Disorders

Individuals with anxiety disorders frequently exhibit physical symptoms such as sweating or elevated heart rate, especially when under stress. Such physiological changes can mirror those seen when a person is being deceptive, complicating the interpretation of polygraph results.

Heart Conditions

Certain heart conditions can trigger increases in heart rate or blood pressure during stressful situations, such as a polygraph test. This response can lead to false-positive results, where an innocent person appears deceptive.


Certain drugs, like beta-blockers, can alter heart rate and blood pressure, leading to potential inaccuracies in polygraph test results.


Pregnancy can cause hormonal fluctuations that might distort the readouts on some polygraph instruments. Therefore, pregnant women are advised to notify the examiner before the test.

Sleep Deprivation

Lack of sleep can result in heightened physiological responses that may mimic those associated with deception, leading to potential false positives.


Even minor illnesses can alter physiological responses and potentially skew polygraph results.

Neurodiverse Individuals & Mental Disabilities

Individuals on the autism spectrum or with other mental disabilities may find it difficult to control their emotions and physiological responses, complicating the interpretation of their polygraph tests.

Obesity & Large Body Size

People with obesity or larger bodies may struggle with normal breathing during testing, which could create false positives.

Drug Use

Certain drugs can directly affect physiological functions measured during a polygraph test.

Alcohol Withdrawal

Withdrawal from alcohol can trigger a sympathetic nervous system response, which would appear as deception on many types of polygraphs.

If you have a medical condition that may affect your polygraph results, it is essential to discuss it with your examiner before the test commences. This open dialogue allows the examiner to adjust their testing procedures, ensuring fairness and accuracy.

However, it’s also important to note that while medical conditions can influence polygraph results, these influences do not invalidate the use of polygraphs. Instead, they emphasize the need for trained and experienced examiners who can appropriately adjust their procedures and interpretations in light of such conditions.

Remember, medical conditions or drugs do not automatically mean that a polygraph test will be invalid or inaccurate. Each situation must be assessed on its individual merits, taking into account the specifics of the person’s condition or medication, the nature of the questions asked, and the overall context of the test.

To learn more about how your specific health condition could affect the results, consult with an accredited professional in polygraph testing. They will be able to offer detailed information about the potential impact and guide you through the process to ensure accuracy and fairness.