Sleep Studies: Testing, Results & Sleep Evaluation
A sleep study is the gold standard for diagnosing sleep disorders like sleep apnea, narcolepsy, and periodic limb movement disorder. Whether you are considering testing for the first time or trying to understand your results, our evidence-based guides walk you through every step.
What Is a Sleep Study?
A sleep study (polysomnography) is an overnight test that records your brain waves, heart rate, breathing, oxygen levels, and body movements while you sleep. It is the primary diagnostic tool used by sleep medicine physicians to identify conditions like obstructive sleep apnea (OSA), central sleep apnea, narcolepsy, restless legs syndrome, and REM behavior disorder.
Sleep studies can be conducted in an accredited sleep lab (in-facility) or at home using portable monitoring devices (HSAT). Your doctor will recommend the appropriate type based on your symptoms and medical history.
Sleep Study Guides
What Is a Sleep Study?
A complete guide to sleep studies (polysomnography): what they measure, the different types available, and what to expect during overnight testing.
Home vs Lab Testing
Compare home sleep apnea tests (HSAT) with in-lab polysomnography. Learn the pros, cons, accuracy, and cost differences to choose the right option.
Sleep Study Cost
Current costs for sleep studies in California including in-lab polysomnography, home sleep tests, and what insurance typically covers.
How to Prepare
Step-by-step preparation guide for your upcoming sleep study. What to bring, what to avoid, and how to get the most accurate results.
Results Explained
Learn how to read your sleep study results including AHI scores, sleep stages, oxygen levels, and what your numbers mean for treatment options.
Insurance Coverage
Find out if your health insurance covers sleep studies, what criteria must be met, and how to get prior authorization for testing.
CPAP After Testing
What happens after your sleep study diagnosis. Guide to CPAP titration, choosing equipment, building compliance, and follow-up care.
Types of Sleep Studies
In-Lab Polysomnography (PSG)
The most comprehensive sleep test. Conducted overnight in an accredited sleep center with a technician monitoring multiple body functions including EEG, EMG, EOG, ECG, airflow, and oxygen saturation.
Home Sleep Apnea Test (HSAT)
A portable, simplified test primarily used to diagnose obstructive sleep apnea. Measures airflow, respiratory effort, and blood oxygen. More convenient but less comprehensive than in-lab testing.
Multiple Sleep Latency Test (MSLT)
A daytime test measuring how quickly you fall asleep in quiet situations. Used primarily to diagnose narcolepsy and measure excessive daytime sleepiness. Conducted the day after overnight PSG.
CPAP Titration Study
An overnight study specifically to determine the optimal CPAP pressure setting for treating sleep apnea. May be combined with a diagnostic study (split-night study).