A sleep study helps your doctor understand what’s happening in your body while you sleep. It measures things like your brain waves, breathing, heart rate, and oxygen levels.
You can do a sleep study overnight at home or in a sleep lab. The information it provides helps diagnose sleep disorders and guide treatment so you can sleep and feel better.
What Happens During a Sleep Study?
Testing usually takes place in a sleep lab with trained staff nearby. Results reveal what’s disrupting your sleep and guide the right treatment.
You’ll be connected to several precise sensors designed specifically to measure different functions. Here’s what the sensors measure:
- Electroencephalography (EEG) measures your brain waves, detecting sleep stages (REM, non-REM) and disruptions.
- Electrocardiography (EKG) tracks heart rhythm to detect abnormal patterns potentially linked to sleep apnea or heart disorders.
- Electromyography (EMG) records muscle activity, identifying restless legs syndrome or periodic limb movements during sleep.
- Electro-oculography (EOG) monitors eye movements, crucial for distinguishing sleep stages, particularly REM sleep.
- Breathing sensors and airflow monitors check breathing rates and airflow blockages to pinpoint sleep apnea.
- Respiratory inductive plethysmography (RIP) belts detect chest and abdominal expansion, crucial for distinguishing obstructive versus central sleep apnea.
- Pulse oximeters track oxygen levels in your blood, a key indicator of sleep apnea severity.
- Audio and video recordings capture sleep behaviors like snoring, gasping, or unusual movements synchronized with sensor data.
The sensors don’t hurt, and technicians make sure everything stays in place so the results are accurate. While it may look intimidating at first, the test is simple, comfortable, and non-invasive.
Why Would Your Doctor Recommend a Sleep Study?
Doctors recommend sleep studies when they suspect a hidden sleep disorder. Symptoms like loud snoring, gasping, frequent wake-ups, feeling exhausted during the day, or trouble breathing during sleep often raise this concern. Sleep issues such as these can quietly affect your health, mood, and safety.
Sleep studies help diagnose conditions like:
- Obstructive Sleep Apnea (OSA): Aaffects about 22 million Americans. When left untreated, OSA can raise your risk for stroke, high blood pressure, and heart disease.
- Narcolepsy-Causes sudden sleep attacks or extreme daytime tiredness. It affects roughly 1 in every 2,000 people in the U.S.
- Periodic Limb Movement Disorder (PLMD)-Leads to repeated, uncontrollable limb movements during sleep and affects around 4% of adults.
- Restless Legs Syndrome (RLS)– A neurological condition that causes uncomfortable sensations in the legs, often disrupting sleep. It affects 5 -10% of adults.
- Insomnia and REM sleep disorders-mpacts millions and can lower quality of life while increasing the risk of anxiety and depression.
How Should You Prepare for a Sleep Study?
Preparing is simple:
- Stick to your normal sleep schedule.
- Avoid naps the day of your study.
- Skip caffeine and alcohol for at least 8 hours beforehand.
- Ask your doctor whether you should pause any medications.
Before you arrive, shower but avoid lotions or hair products. Bring comfortable sleepwear and avoid nail polish so the oxygen sensor can read correctly.
What Happens After Your Sleep Study?
In the morning, a technician removes the sensors and explains your next steps.
Your sleep specialist usually reviews your results within 1–2 weeks. They analyze your brain waves, breathing patterns, oxygen levels, and movements to see whether a sleep disorder is present.
During your follow-up visit, your doctor will explain the findings and discuss treatments such as:
- CPAP therapy for sleep apnea
- Medications or behavioral therapy for insomnia or RLS
- Lifestyle changes, like better sleep habits or weight management
Some people may need additional testing or specialist care based on their results.
Are At-Home Sleep Studies Accurate?
At-home sleep studies (Home Sleep Tests or HSTs) are helpful for checking for obstructive sleep apnea. They’re simple, affordable, and often required by insurance first.
However, home tests only measure a few things: breathing patterns, airflow, oxygen levels, and heart rate. They don’t record brain waves, eye movements, or muscle activity, signals that are important when diagnosing conditions like narcolepsy, periodic limb movement disorder (PLMD), or REM sleep behavior disorder (RBD).
That’s where the limits show. Research has found that home tests miss a good number of OSA cases. False negatives happen in over 17% of cases, meaning the test may say you don’t have sleep apnea when you actually do (1).
At The Insomnia and Sleep Institute of Arizona, we frequently see patients who passed a home test but still show clear signs of sleep apnea. In these cases, an in-lab study provides a more complete and accurate picture.
Additionally, advanced testing options at The Insomnia and Sleep Institute of Arizona include:
- Multiple Sleep Latency Test (MSLT): Essential for diagnosing narcolepsy by evaluating daytime sleepiness patterns following overnight PSG.
- CPAP Titration Studies: Identify optimal treatment pressures for patients diagnosed with OSA or central sleep apnea (CSA).
- Advanced Brain Monitoring Sleep Profiler EEG: This offers sophisticated home EEG monitoring for insomnia evaluations, exceeding basic home sleep test capabilities.
How Can You Improve the Accuracy of Your Diagnosis?
You can help ensure accurate results by:
- Following your provider’s testing recommendations
- Sharing all symptoms and sleep concerns during your consultation
- Understanding insurance requirements, especially if a home test is needed first
Our benefits coordinators can help you with coverage, authorizations, and scheduling follow-up testing.
Schedule Your Consultation with Our Experts Today
At The Insomnia and Sleep Institute of Arizona our board-certified sleep specialists serve patients across Scottsdale, Phoenix, and Gilbert.
Why patients choose us:
- You always see a sleep-medicine specialist
- We offer advanced diagnostic testing
- We provide clear answers and insurance support
- Our clinics are designed for comfort and accuracy
References
Stretch, R., Ryden, A., Fung, C. H., Martires, J., Liu, S., Balasubramanian, V., Saedi, B., Hwang, D., Martin, J. L., Penna, N. D., & Zeidler, M. R. (2019). Predicting Nondiagnostic Home Sleep Apnea Tests Using Machine Learning. Journal of Clinical Sleep Medicine, 15(11), 1599–1608. https://doi.org/10.5664/jcsm.8020
Disclaimer: The information provided in this blog post is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always consult with a licensed healthcare provider for recommendations specific to your individual health needs.
