A sleep study, also known as polysomnography (PSG), is a test used to diagnose sleep disorders. During a sleep study, various physiological parameters are monitored while the individual sleeps. These parameters typically include:
- Brain waves (Electroencephalogram, EEG): Monitoring brain activity to determine sleep stages and detect abnormalities such as sleep apnea or narcolepsy.
- Eye movements (Electrooculogram, EOG): Tracking eye movements to identify REM (rapid eye movement) sleep, which is associated with dreaming.
- Muscle activity (Electromyogram, EMG): Recording muscle tone and activity to detect disorders like periodic limb movement disorder or REM sleep behavior disorder.
- Heart activity (Electrocardiogram, ECG or EKG): Monitoring heart rate and rhythm to identify abnormalities such as arrhythmias.
- Breathing patterns: Monitoring airflow through the nose and mouth to detect disruptions indicative of sleep apnea or other respiratory disorders.
- Oxygen levels: Measuring blood oxygen saturation (oximetry) to detect dips in oxygen levels during sleep, which can indicate sleep apnea or other breathing-related issues.
- Body position: Tracking body movements and position changes during sleep.
Sleep studies are typically conducted in a sleep center or laboratory, where the individual spends the night while being monitored by specialized equipment. In some cases, home sleep studies may be conducted with portable monitoring devices, though these may not provide as comprehensive data as in-lab studies.
The results of a sleep study can help diagnose various sleep disorders such as sleep apnea, insomnia, narcolepsy, restless legs syndrome, and others. Based on the findings, healthcare providers can recommend appropriate treatment options, which may include lifestyle changes, medication, or the use of devices such as continuous positive airway pressure (CPAP) machines for sleep apnea.