An overnight sleep study is a diagnostic test that monitors your body while you sleep to identify sleep disorders such as sleep apnea, insomnia, and restless legs syndrome. During the study, sensors track key biological signals including breathing patterns, oxygen levels, heart rate, and body movement. If you have been experiencing poor sleep quality, loud snoring, or excessive daytime fatigue, an overnight sleep study can give you the answers you need to start feeling better. Below, we answer the most common questions people have before booking their first sleep study.
What happens during an overnight sleep study?
During an overnight sleep study, sensors are attached to your body to continuously record your breathing, oxygen saturation, heart rate, body position, and limb movements while you sleep. The data collected gives sleep specialists a detailed picture of what is happening in your body throughout the night, making it possible to detect disruptions you may not even be aware of.
Depending on whether you complete the study at home or at a clinic, the setup process varies slightly. For a home-based Level 3 sleep study, a respiratory therapist walks you through how to apply the sensors yourself before bed. The device records your data overnight, and you return it the following day for analysis. The experience is designed to be as comfortable and unobtrusive as possible so that your sleep is as natural as it would be on any other night.
What conditions can an overnight sleep study diagnose?
An overnight sleep study can diagnose a range of sleep-disordered breathing conditions, with obstructive sleep apnea being the most common. It can also help identify central sleep apnea, hypopnea, and oxygen desaturation events that occur during sleep. In some cases, the data gathered also points toward restless legs syndrome or periodic limb movement disorder.
Sleep apnea in particular is frequently undiagnosed because its most disruptive symptoms, such as breathing pauses and drops in blood oxygen, happen while you are unconscious. Many people live with the condition for years, attributing their fatigue, morning headaches, and difficulty concentrating to stress or aging. An overnight sleep study removes the guesswork by providing objective data that your care team can use to make an accurate diagnosis and recommend the right treatment.
What’s the difference between an in-lab sleep study and a home sleep test?
The key difference between an in-lab sleep study and a home sleep test is the setting and the level of monitoring involved. A home sleep test, also called a Level 3 sleep study, is conducted in your own bed using a portable monitoring device. An in-lab study takes place in a clinical environment with a technician present. For most adults with suspected obstructive sleep apnea, a Level 3 home sleep test provides accurate, clinically reliable results.
Level 3 sleep studies are an effective diagnostic tool precisely because they capture real-world sleep data in the environment where you actually sleep. There is no need to adapt to an unfamiliar room or clinical setting, which means the results reflect your typical sleep patterns. Once a diagnosis is confirmed, the path to treatment, most commonly CPAP therapy, can begin quickly. Getting that diagnosis sooner rather than later matters because effective treatment can dramatically improve your energy levels, cardiovascular health, and overall quality of life.
How should you prepare for an overnight sleep study?
To prepare for an overnight sleep study, you should avoid caffeine and alcohol on the day of the study, follow your normal daily routine as closely as possible, and arrive or set up with clean, dry hair since sensors adhere better to clean skin and scalp. Wearing comfortable, loose-fitting sleepwear is also recommended.
A few additional steps help ensure the data collected is as accurate as possible:
- Avoid napping during the day before the study so you are naturally tired at your usual bedtime
- Take any regular medications as prescribed unless your care team advises otherwise
- Bring or prepare everything you normally use at bedtime, such as a pillow or white noise machine, to recreate your typical sleep environment
- If you are completing a home sleep test, review the sensor setup instructions with your respiratory therapist in advance so you feel confident applying the device on your own
The goal is to make the night as representative of your normal sleep as possible. The more accurately the study reflects your typical night, the more useful the results will be for your care team.
How long does it take to get sleep study results?
Sleep study results are typically available within one to two weeks after the study is completed. Once the data has been collected, a sleep specialist reviews and interprets the recordings before preparing a report for your care team. The timeline can vary slightly depending on clinic volume and the complexity of the data.
At Dream Sleep Respiratory, we aim to move patients through the diagnostic process efficiently so that treatment can begin as soon as possible. Delays in diagnosis often mean delays in treatment, and for conditions like sleep apnea, starting CPAP therapy sooner can lead to faster improvements in sleep quality, daytime alertness, and long-term health outcomes. If you have questions about your results or what they mean, our respiratory therapists are available to walk you through everything in plain language.
Does Alberta Health Care cover the cost of a sleep study?
Alberta Health Care (AHCIP) does cover certain sleep study services, but coverage depends on the type of study ordered and whether it has been physician-referred. A Level 3 home sleep test ordered through an appropriate referral pathway may be eligible for coverage. It is worth confirming the specifics of your coverage before booking, as individual circumstances can vary.
For patients who are self-referred or whose coverage situation is unclear, our team can help you understand your options and navigate the process. The cost of leaving a sleep disorder undiagnosed and untreated, both in terms of health and quality of life, is far greater than the cost of a sleep study. Effective treatment through CPAP therapy can reduce the risk of serious health complications, improve mood, sharpen focus, and restore the kind of deep, restorative sleep that makes a genuine difference to daily life.
How Dream Sleep Respiratory helps you get the answers you need
At Dream Sleep Respiratory, we make the journey from poor sleep to real answers as straightforward as possible. We offer Level 3 home sleep studies that are accurate, accessible, and designed around your lifestyle. Our team of experienced respiratory therapists and sleep specialists guides you through every step, from the initial setup of your sleep test to the interpretation of your results and the creation of a personalized treatment plan.
Here is what you can expect when you work with us:
- A home-based Level 3 sleep study that you complete in the comfort of your own bed
- Clear, timely results reviewed by qualified sleep specialists
- A personalized care plan that may include CPAP therapy, lifestyle guidance, or other interventions
- Ongoing support, including follow-up appointments and CPAP machine adjustments
- Clinic locations across Alberta, including Calgary, Edmonton, Red Deer, Canmore, Cochrane, Olds, and Lethbridge
If you have been struggling with your sleep and want real answers, we are here to help. Contact us today to book your overnight sleep study and take the first step toward better sleep and better health.
Frequently Asked Questions
Can I take sleeping pills the night of my sleep study if I have trouble falling asleep?
It is generally best to avoid sleeping pills on the night of your sleep study unless your care team has specifically told you otherwise, as some medications can suppress certain sleep stages or affect your breathing patterns, which may alter the accuracy of your results. If you are concerned about being able to fall asleep with the sensors on, let your respiratory therapist know in advance — they can offer practical tips to help you relax and settle in naturally.
What if I can't sleep well during the study? Will the results still be accurate?
It is very common to sleep somewhat differently than usual during a sleep study, and sleep specialists account for this when interpreting your results. Even a few hours of recorded sleep can provide enough data to detect significant events like apnea episodes, oxygen desaturations, or limb movements. If the data collected is insufficient for a reliable diagnosis, your care team will discuss whether a repeat study is needed.
How do I know if I actually need a sleep study, or if my tiredness is caused by something else?
Key signs that a sleep study may be appropriate include loud or frequent snoring, waking up gasping or choking, morning headaches, unexplained daytime fatigue despite getting enough hours of sleep, and difficulty concentrating throughout the day. If you are unsure, speaking with your family physician or contacting a sleep clinic directly is a great first step — a brief intake conversation can help determine whether a sleep study is the right diagnostic tool for your symptoms.
What happens after I receive my sleep study results — what are the next steps?
Once your results are reviewed by a sleep specialist, your care team will walk you through what the data shows and recommend a treatment plan tailored to your diagnosis. For obstructive sleep apnea, this most commonly involves starting CPAP therapy, which uses gentle air pressure to keep your airway open while you sleep. Your respiratory therapist will help you select the right CPAP equipment, fit your mask, and schedule follow-up appointments to ensure the therapy is working effectively for you.
Is a Level 3 home sleep test as accurate as an in-lab study for diagnosing sleep apnea?
For adults with a moderate-to-high likelihood of obstructive sleep apnea, Level 3 home sleep tests are clinically validated and widely accepted as an accurate diagnostic tool — Canadian sleep medicine guidelines support their use as a first-line option. Because the test is conducted in your own sleep environment, the data often reflects your typical night more faithfully than an in-lab study would. However, if your symptoms are complex or a home test result is inconclusive, your care team may recommend an in-lab study for a more comprehensive assessment.
Can children undergo an overnight sleep study, or is it only for adults?
Sleep studies can be performed on children, though pediatric sleep assessments typically require an in-lab polysomnography rather than a home sleep test, as children need more comprehensive monitoring and closer supervision during the study. If your child snores heavily, has pauses in breathing during sleep, or struggles with hyperactivity and attention issues that may be linked to poor sleep, speaking with your pediatrician about a referral to a pediatric sleep specialist is the recommended first step.
What if my sleep study results come back normal but I still feel like something is wrong with my sleep?
A normal sleep study result rules out sleep-disordered breathing conditions like obstructive sleep apnea, but it does not mean your sleep concerns are not real or worth investigating further. Other factors such as insomnia, circadian rhythm disorders, anxiety, thyroid issues, or poor sleep hygiene can significantly affect sleep quality without being detectable on a Level 3 home sleep test. In this case, your care team can help guide you toward the appropriate next steps, which may include a different type of sleep evaluation or a referral to another specialist.