Polysomnography (In-Lab Sleep Study)
A comprehensive overnight sleep study conducted in a sleep laboratory that monitors brain waves, breathing, heart rhythm, oxygen levels, and muscle activity to diagnose sleep disorders.
What is Polysomnography (In-Lab Sleep Study)?
Polysomnography (PSG) is the gold-standard diagnostic test for sleep disorders. Conducted overnight in a sleep laboratory, PSG comprehensively monitors multiple body functions during sleep including brain activity (EEG), eye movements (EOG), muscle tone (EMG), heart rhythm (ECG), breathing effort and airflow, oxygen saturation, and leg movements. This wealth of data allows sleep specialists to accurately diagnose a wide range of sleep disorders and determine their severity.
How It Works
During a PSG, a sleep technologist applies sensors to your scalp, face, chest, and legs using adhesive and tape. These sensors connect to monitoring equipment that records data throughout the night. You sleep in a private, hotel-like room while a technologist monitors your study from an adjacent control room. The recorded data is later analyzed by a sleep physician who scores sleep stages and identifies any abnormal events.
Who Is It For?
PSG is recommended when sleep apnea is suspected but home testing is not appropriate, when other sleep disorders (narcolepsy, parasomnias, nocturnal seizures, periodic limb movements) are suspected, for CPAP titration studies, and when initial testing is inconclusive. Certain conditions like significant cardiopulmonary disease, potential central sleep apnea, or safety-sensitive occupations may require in-lab testing.
Benefits
Comprehensive Monitoring
PSG monitors far more parameters than home testing, enabling diagnosis of conditions that can't be detected at home, including sleep stages, arousals, and detailed respiratory events.
Professional Oversight
A trained technologist monitors your study and can intervene if needed—adjusting sensors, noting events, or initiating CPAP if part of a split-night study.
Accurate Sleep Staging
EEG monitoring allows precise measurement of sleep architecture, including REM sleep, which is important for diagnosing conditions like REM sleep behavior disorder and narcolepsy.
Split-Night Studies
If severe sleep apnea is diagnosed in the first half of the night, CPAP titration can begin immediately, completing diagnosis and treatment in one night.
Diagnoses Multiple Disorders
PSG can identify sleep apnea, narcolepsy, periodic limb movement disorder, REM sleep behavior disorder, parasomnias, and nocturnal seizures in a single study.
Side Effects & Considerations
Most side effects are minor and can often be resolved with simple adjustments.
First-Night Effect
Sleeping in an unfamiliar environment with sensors attached may affect sleep quality. However, this rarely prevents accurate diagnosis of significant sleep disorders.
Inconvenience
Requires spending a night away from home, typically arriving in the evening and leaving in the morning. May require time off work.
Sensor Discomfort
The sensors and wires, while not painful, can feel unusual and may take some time to adjust to. Most patients sleep adequately despite them.
Waiting Time
In-lab sleep studies may have longer wait times for scheduling compared to home tests, depending on local availability.
Higher Cost
PSG is more expensive than home sleep testing, though most insurance covers it when medically necessary.
Variations & Types
Diagnostic PSG
Standard overnight study to diagnose sleep disorders without any treatment intervention during the study.
Split-Night PSG
If severe OSA is identified in the first 2-3 hours, CPAP titration begins for the remainder of the night, combining diagnosis and titration.
CPAP Titration Study
Full-night study for patients already diagnosed with sleep apnea, focused on finding the optimal CPAP pressure setting.
BiPAP/ASV Titration
Specialized titration study for patients who need BiPAP or adaptive servo-ventilation therapy.
Extended EEG Monitoring
Additional EEG leads for patients with suspected nocturnal seizures or unusual nocturnal behaviors.
Tips for Success
Maintain Normal Routine
Follow your usual daytime routine before the study. Don't nap, avoid caffeine after noon, and don't use alcohol—you want the study to reflect your typical sleep.
Bring Comfort Items
Bring your own pillow, pajamas, and any items that help you sleep. Most labs accommodate personal preferences.
Shower Before Arrival
Clean hair and skin help sensors stick better. Avoid hair products, lotions, and makeup on the night of your study.
List Your Medications
Bring a list of all medications. Some may affect sleep and will be noted in your study interpretation.
Arrive Prepared to Sleep
Eat dinner before arriving. Complete your bedtime routine (brushing teeth, etc.) before the technologist begins setup.
Communicate Needs
Let the technologist know if you need to use the bathroom, adjust room temperature, or if something is uncomfortable. They're there to help.
Additional Resources
Find Providers
Search our directory for sleep clinics that offer polysomnography (in-lab sleep study).
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