What Are the Benefits of Polysomnography?
Radiology Data Verified

Polysomnography - Uses and Techniques

Published on Feb 06, 2023   -  4 min read


Polysomnography is a diagnostic study of sleeping disorders. Read the article below to learn about the uses and procedures of polysomnography.


Polysomnography is a diagnostic test performed during sleep. The sleep patterns are recorded by medical professionals to diagnose the sleeping disorder. It is also helpful to plan the treatment procedures depending on the sleeping disorders. It is a painless and non-invasive technique. The data is provided in the form of a graph. A video may be recorded by the medical provider to observe the change in posture.

What Are the Various Patterns Measured in Polysomnography?

  • Electroencephalography - The electrical activity of the brain is due to the presence of neurotransmitters. It is used to observe brain activity with the help of brain waves.

  • Electrooculogram - Electrooculogram is used to measure the movement of the eyes. The number of movements and the frequency of movement are assessed.

  • Electromyography - It is used to measure muscle tone during the action. The movement of limbs is analyzed using electromyography. The number and the intensity of the limb movements are measured. Both the upper and lower limbs are observed.

  • Breathing Pattern - The number of inspirations and expiration and the intensity of the respiration are evaluated in the breathing pattern. It also estimates the oxygen saturation level in the blood.

  • Sleep Pattern - The time taken by the individual to fall asleep is assessed. This is known as sleep latency. It is used to observe the amount of sleep that a person gets in the night. The ratio of sleep time to the time in bed is calculated. This is known as sleep efficiency. The pH level (acid-base) of the stomach is examined. It is used to identify the amount of acid secretion during sleep.

How Is the Polysomnography Procedure Performed?

The polysomnography is carried out in the following process;

  • The individuals must remove the ornaments and wear an outpatient dress given in the sleep center.

  • The individual should stay in the sleep center during the night until the completion of the sleep study.

  • The electrodes are attached to the head and body with cables. These metal plates are used to calculate electroencephalography, electrooculogram, and electromyography.

  • A pulse oximeter tool is used to measure the oxygen level in the bloodstream. It is placed over the fingers. It monitors the airflow during sleep.

  • The temperature is adjusted to the normal level in the room. The activity of the individual is monitored before and after sleeping.

  • The lights are turned off. The individual can use a blanket if necessary. It will not interfere with the electrodes attached.

  • If the patient wakes up frequently, then the multiple sleep latency can be calculated.

The same process is repeated daily until the end of the sleep study.

What Are the Instructions to Follow During Polysomnography?

There are a few general instructions to follow during polysomnography. They are as follows;

  • The individual should answer certain questions related to bedtime and sleep provided by the medical professional. Avoid taking short naps in the afternoon during the sleep study.

  • The vitamin supplements and the medications taken for systemic disease must be informed to the medical professional. Avoid sedatives during the study because these drugs may influence sleep.

  • The individual must avoid caffeine-related drinks during the sleep study. Try to stop it a few days before the sleep study or polysomnography.

  • Take showers before going to the sleep centers. It helps in sleeping. Do not use body lotions as it affects the electrodes.

  • The person undergoing this test should report in the evening to finish a few protocols.

  • They are then allowed to enter a sleeping room that is dark, cold, and quiet to induce sleep.

  • At least two hours of sleep is necessary to caliber the recordings.

What Are the Uses of Polysomnography?

Polysomnography is used to evaluate sleeping dysfunctions. They are as follows;

  • Sleep Apnea - Sleep apnea is a condition in which the breathing cycle stops continuously and restarts during sleep. So the individual tries to gasp for air after the pause. This disturbs sleep, and the individual wakes up frequently during the night. A loud sound is heard from the patient during snoring. This results in restlessness and fatigue during the daytime.

  • Narcolepsy - Narcolepsy occurs due to nervous disorders. The patient falls asleep during the day and stays awake at night. There is increased drowsiness during the day. It affects teens. There is a fragmented sleep pattern in narcolepsy.

  • Seizure Disorders - The abnormal electrical activity of the brain results in multiple seizures. The patient undergoes stress and is unable to sleep. Multiple seizures in a day make the patient unconscious in the worst cases. It occurs due to metabolic disturbances in the body.

  • Restless Legs Syndrome - The individual has an intense feeling of moving the leg, especially during sleep. This frequent sensation interferes with the sleep cycle. Eventually, it leads to sleep deprivation. It mostly affects females. The limb movement lasts for 40 seconds to one minute. This urge causes a pulling sensation and disturbs sleep.

  • Rapid Eye Movement (REM) Sleep Behavior Disorder - Vivid dreams during sleep cause rapid eye movement (REM) sleep behavior disorder. It occurs due to the degeneration of neurons in the brain. Some individuals do explicit actions like talking, jumping, and punching during sleep. It is diagnosed using polysomnography and can be treated with medications.

  • Insomnia - Chronic condition of trouble falling asleep is called insomnia. The person is unable to sleep and does not feel fresh after waking up. It impacts mental health. The individual has inconsistent sleep patterns. The person feels irritated and has constant mood swings. So sleep study is used to diagnose insomnia.


Polysomnography can also be performed at home, but it has limited sensors. However, a sleep study does not require complete sleep. A home sleep study is mainly used for diagnosing obstructive sleep apnea. If the sleep study is done at sleep centers, then the sensors are removed in the morning. The individual can continue the normal activities in the morning. The results of the sleep study made in sleep centers are given in three weeks. Untreated sleeping disorders can lead to an increase in blood pressure, depression, stroke, and cardiac issues. However, these tests help determine the issue so that appropriate treatment can be started to improve the patient's quality of life.

Last reviewed at:
06 Feb 2023  -  4 min read




Comprehensive Medical Second Opinion.Submit your Case

Related Questions & Answers

Why do I have excessive daytime sleepiness? How to treat it?

Query: Hi doctor, I am a 16-year-old female. My weight is 85 kilograms, and I have a height of 5 feet 3 inch. I have excessive daytime sleepiness for the past three years. It got started in me before three years, and my parents took me to the local GP immediately. They did blood tests and told that I have...  Read Full »

Please suggest the diagnosis on my EEG report as I could not sleep.

Query: Hello doctor, Could you please analyze the electroencephalogram (EEG) recording enclosed and provide me with a detailed diagnosis? The reason for this examination is that I have problems falling and staying asleep for two years. I sleep only three to four hours a day, with common medication not or p...  Read Full »

How can I get rid of snoring?

Query: Hello doctor, Sometimes, I snore at night. It disturbs my wife. If I turn on my side, the snoring stops. But can you suggest ways to cure the snoring?  Read Full »

Popular Articles Most Popular Articles

Do you have a question on Polysomnography or ?

Ask a Doctor Online

* guaranteed answer within 4 hours.

Disclaimer: No content published on this website is intended to be a substitute for professional medical diagnosis, advice or treatment by a trained physician. Seek advice from your physician or other qualified healthcare providers with questions you may have regarding your symptoms and medical condition for a complete medical diagnosis. Do not delay or disregard seeking professional medical advice because of something you have read on this website. Read our Editorial Process to know how we create content for health articles and queries.