Polysomnography

Polysomnography, commonly called a sleep study, is a diagnostic test used to monitor various body functions while a person sleeps. It is particularly useful for evaluating sleep-related breathing disorders such as obstructive sleep apnea, in which breathing repeatedly becomes reduced or interrupted during sleep. During a polysomnography study, several physiological signals may be recorded, depending on the type of study being performed.

These can include breathing patterns, airflow, oxygen saturation, heart rate, body movements, brain activity, and other parameters related to sleep and breathing. The information collected helps healthcare professionals understand what happens during different stages of sleep and whether there are repeated breathing disturbances or other abnormalities.

A sleep study may be recommended for people who have symptoms such as loud or persistent snoring, witnessed pauses in breathing during sleep, waking with a choking or gasping sensation, excessive daytime sleepiness, morning headaches, disturbed sleep, or unexplained fatigue. It may also be considered when there is a clinical suspicion of sleep apnea or another sleep-related disorder. Depending on the patient's circumstances, the study may be performed in a sleep facility or, for selected patients, using an appropriate home-based monitoring system.

In a sleep laboratory, sensors are applied to the body to record the required signals while the patient sleeps. The equipment is designed to monitor the relevant physiological information without preventing normal sleep as much as possible. After the study, the recorded data is analysed by an appropriately trained healthcare professional. The results can help determine whether sleep-related breathing disturbances are present and, when applicable, provide information about their frequency and severity.

Polysomnography is different from sleep endoscopy: a sleep study measures physiological changes during sleep, whereas sleep endoscopy is used to observe the upper airway during a controlled sleep-like state. The findings from a sleep study are considered together with the patient's symptoms and medical history to determine the next steps. Depending on the results, management may include lifestyle measures, treatment of nasal or airway problems, positive airway pressure therapy, oral appliances, or selected surgical options. A properly conducted sleep study can therefore provide important objective information for diagnosing and managing sleep-related breathing disorders.