Understanding Your Sleep Study Results

What Do the Numbers Mean?

The information gathered during your sleep study—either a home study (HST) or an in-lab study (PSG)—are used to determine your problem and the severity of it. And, while the numbers do tell your doctor a lot, there’s more to helping you than JUST the numbers.

During the study the number of times you stop breathing(apnea)or breath too shallowly(hypopnea)are recorded. Reduction in the level of oxygen(oxygen desaturation)in your blood is also noted. This information is used to classify the presence and severity of obstructive sleep apnea (OSA).

Types of airway obstructions:

  • Apnea—a complete collapse of the airway, breathing stops for 10 seconds or more and airflow to the lungs is blocked.
  • Hypopnea—a partial collapse of the airway, breathing is reduced for 10 seconds or more and airflow to the lungs is restricted.

The Apnea Hypopnea Index (AHI)is the number of apneas and hypopneas per hour of sleep. It is calculated by adding the apneas and hypopneas together and then dividing that number by the number of hours you slept, like this:

AHI= Apneas + Hypopneas

Total hours of sleep

Once you have your AHI you can use this table to Classify your OSA severity:


Severity of OSA




Mild OSA


Moderate OSA


Severe OSA

Your sleep study results may also include another number called the Respiratory Disturbance Index (RDI). This number includes apneas, hypopneas and other additional breathing irregularities. So, the RDI is often higher than the AHI.

When having episodes of apnea or hypopnea during OSA, the level of oxygen in your blood may fall, depriving your body of much needed oxygen. This is known as oxygen desaturation, and is another number you will find on your sleep study.

At sea level, normal blood oxygen saturation is usually around 96-97%. During sleep a desaturation to 90% is generally considered mild, dips to 80-89% moderate and below 80% severe.


The Oxygen Desaturation Index (ODI)is another index on your sleep study report. This index is measured by the number of times per hour that the oxygen level in your blood drops by a certain percentage from your baseline number. The American Academy of Sleep Medicine (AASM) counts a 3% drop as a desaturation and Medicare uses a 4% drop.

Once you have your sleep study results, you and your doctor can review them and then based on the presence, severity of the disease and individual factors can determine the best course of treatment for you.

Understanding your numbers is important, but they are only one part of the complex puzzle making up your sleep. The treatment decision that YOU and your doctor will make should take into account many different variables to help you achieve your ultimate goal of restful, refreshing and health-promoting sleep.

1. Understanding Your Sleep Study Test Results: A Comprehensive Guide

If you have recently undergone a sleep study, understanding the test results can be confusing.
Here is a comprehensive guide to understanding your sleep study test results to help you better understand your sleep.

Total Sleep Time (TST)
This is the amount of time from the beginning of the test until you woke up in the morning. It includes both time spent sleeping and any time spent awake during the study.
Sleep Latency
This is the amount of time it takes you to fall asleep once the study has begun. It is typically measured in minutes.
Sleep Efficiency
This measures the amount of time you spent sleeping during the sleep study as a percentage of the total sleep time. The higher the percentage, the more efficient your sleep was.
Stage of Sleep
The sleep cycle consists of four stages, with the first three being non-REM sleep and the fourth being REM sleep. The stage of sleep you are in during the study determines the type of sleep you are getting.
REM Sleep
This is the phase of sleep where your eyes move rapidly, and your brain activity resembles that of being awake. During REM sleep, you experience vivid dreams.
Obstructive Sleep Apnea (OSA)
This is a respiratory disorder that causes you to stop breathing during sleep. Obstructive sleep apnea occurs when the muscles in the throat collapse, blocking the airway.
Apnea-Hypopnea Index (AHI)
This measures the severity of sleep apnea in your sleep study. It is calculated by dividing the number of obstructive apneas and hypopneas by the hours of sleep.
This is a partial obstruction of the airway during sleep, resulting in a decrease in airflow.
Oxygen Saturation
This measures the amount of oxygen in your blood. A decrease in oxygen saturation can indicate sleep apnea.
Deep Sleep
This is the stage of sleep associated with physical restoration and growth.
Eye Movement
Rapid eye movement during REM sleep is important for brain function and memory formation.
Severe Sleep Apnea
This is a sleep apnea severity level in which an individual’s breathing is interrupted more than 30 times per hour of sleep.
This refers to the breathing pattern of an individual during sleep.
Snoring is a common symptom of sleep apnea.
The airway refers to the passage that allows air to move from the nose and mouth to the lungs.
Obstructive Apneas
This sleep apnea typically occurs when the airway is blocked, causing a pause or a reduction in breathing.
Sleep Lab
This is a facility where you can undergo an in-lab sleep study to diagnose sleep disorders.
Home Sleep Apnea Test
This is an alternative to an in-lab sleep study where individuals record their sleep patterns at home using a portable monitor.
American Academy of Sleep Medicine
This organization sets standards and guidelines for sleep medicine professionals and sleep studies.
Sleep Specialist
This is a medical doctor who specializes in sleep medicine like Doctor Carmine Morreale

Doctor Carmine Morreale Breathe Well, Sleep Well, Live Well Free eBook

2. The Link Between Sleep Apnea and Heart Disease: What You Need to Know

Sleep apnea is a potentially serious sleep disorder that can have a significant impact on your health. This condition causes interruptions in your breathing while you sleep, which can lead to decreased oxygen levels and a host of related health problems. In fact, research has shown that sleep apnea is strongly linked to an increased risk of heart disease.
If you suspect that you may have sleep apnea, it is important to get a sleep study to assess the severity of your condition. This typically involves spending a night at a sleep center, where your sleep will be monitored using a variety of techniques, such as polysomnography.
During the sleep study, your doctor will assess your sleep stage, oxygen level, and other factors to determine whether you have sleep apnea and what type it may be. There are two main types of sleep apnea: obstructive sleep apnea, which occurs when the airway is physically blocked, and central sleep apnea, which occurs when the brain fails to send the proper signals to the muscles that control breathing.
The results of your sleep study may reveal that you have sleep apnea, and your doctor or sleep specialist will interpret the results to help you understand the severity of your condition and recommend the next steps. In some cases, a home sleep study may be sufficient to diagnose sleep apnea.
If you are diagnosed with sleep apnea, there are a variety of treatment options available, including dental sleep medicine, positive airway pressure therapy, and lifestyle changes. Your doctor or sleep specialist can help you choose the best approach based on your individual needs and the severity of your sleep apnea.
Understanding the different stages of sleep and how they affect your overall sleep architecture is also important. There are four stages of non-rapid eye movement sleep (NREM) and one stage of rapid eye movement (REM) sleep. Each stage has specific characteristics that affect the quality of your sleep.
During the sleep study, your doctor will also assess any leg movements and other symptoms that may be affecting your sleep. Certain sleep disorders, such as restless leg syndrome, can also affect the quality of your sleep and may need to be addressed.
In summary, a sleep study is an important tool for assessing the severity of sleep apnea and other sleep disorders. Understanding the results of your study can help you take action to improve the quality of your sleep and reduce your risk of related health problems.

3. Sleep Study Basics: Types of Sleep Studies and What They Measure 

Sleep studies, also known as polysomnography, are essential diagnostic tools used to evaluate a person’s sleep health. They involve monitoring various bodily functions such as brain waves, heart rate, and breathing during sleep. Here are some basics of sleep studies that you need to know:
Types of Sleep Studies:
1. In-Lab Sleep Study: In this type of study, you spend a night at a sleep laboratory where technicians monitor your sleep using various sensors and equipment.
2. Home Sleep Apnea Study: In this type of study, you spend a night at home with a portable monitor attached to your body to diagnose sleep apnea.

What Do Sleep Studies Measure?
1. Brain activity: Electrodes placed on your scalp record your brain waves to determine when you are awake, in deep sleep, or in REM sleep.
2. Eye movement: Electrodes placed near your eyes monitor your eye movements to detect when you are in REM sleep.
3. Oxygen levels: A clip attached to your finger measures the amount of oxygen in your blood.
4. Heart rate and rhythm: Electrodes placed on your chest monitor your heart function.
5. Breathing: Sensors placed near your nose and mouth record your breathing patterns, including any pauses or obstructions during sleep.

Sleep Study Results:
1. Throughout the night, the sleep technician monitors your sleep data and records any abnormalities.
2. The sleep test results are analyzed and reviewed by a sleep doctor or a sleep specialist who interprets the data and makes a diagnosis.
3. Depending on the results, the doctor may recommend further testing or treatment options.

Understanding Sleep:
1. Sleep is divided into four cycles of sleep, including N1, N2, N3, and REM sleep.
2. N2 is a stage of sleep where you spend most of your time asleep, and it plays a critical role in memory, learning, and mood regulation.
3. A shallow breathing pattern during sleep can lead to a condition called sleep apnea, which can worsen over time if left untreated.
4. Central apneas are another type of breathing disorder during sleep, where the brain fails to send signals to the muscles that control breathing.
5. Understanding your sleep and REM patterns can help you better understand your sleep quality and how it affects your daily life.

Overall, a sleep study is a critical tool for diagnosing and treating sleep disorders. Whether it’s to determine a treatment plan or to understand your sleep quality, there’s no denying the importance of monitoring your sleep health.  

4. Can Home Sleep Tests Accurately Diagnose Sleep Apnea?

Home sleep tests can accurately diagnose sleep apnea in many cases. These tests, also known as portable sleep monitoring devices, measure various aspects of a person’s sleep, including breathing, oxygen levels, and snoring.
However, it is important to note that home sleep tests are not always appropriate for everyone.
Patients with complex medical conditions or other sleep disorders may need a more comprehensive evaluation. In these cases, a full overnight sleep study in a sleep center is recommended.

A baseline sleep study is important for diagnosing sleep disorders like sleep apnea because it provides a detailed picture of the patient’s sleep patterns.
This information can help doctors determine the best course of treatment.
Sleep apnea can affect the sleep of a person by causing snoring, restless sleep, and waking up feeling tired.
In some cases, sleep apnea can be worse during rapid eye movement sleep, which is the stage of sleep associated with dreaming.
During an overnight sleep study, patients are monitored for levels of sleep, including deep sleep and REM sleep.
This information can help doctors understand how sleep apnea may be affecting the patient’s sleep.
Obstructive apneas and central apneas are two types of sleep apnea that can be detected during a sleep study.
Obstructive apneas occur when the airway is blocked during sleep, while central apneas occur when the brain fails to signal the body to breathe.
If you are experiencing symptoms of sleep apnea, such as feeling tired during the day, it is important to talk to one of our doctors at BCOH. They can recommend a sleep study to determine the cause of your symptoms and develop a treatment plan to help you sleep as well as possible.

5. Sleep Disorder Myths Debunked: Separating Fact from Fiction

Sleep Disorder Myths Debunked: Separating Fact from Fiction
Sleep disorders can be confusing and often come with many misinterpretations that could be harmful to your health. Here are some myths and truths you need to be aware of:
Myth: N2 sleep is not important
Truth: N2 sleep is an essential part of the sleep cycle. It is less deep than other stages of sleep, but it is important for consolidating memories, repairing tissues, and boosting the immune system.
Myth: Sleep apnea is not that bad.
Truth: Sleep apnea is a serious sleep disorder that disrupts breathing during sleep. It can lead to a host of issues, including high blood pressure, heart disease, stroke, and even death.
Myth: Leaving the sleep disorder untreated won’t hurt.
Truth: Untreated sleep disorders can lead to many detrimental effects on your health, including high blood pressure, mood changes, memory problems, and a weakened immune system.
Myth: A sleep study only begins in the hospital.
Truth: Sleep studies can be performed at home, and the results are just as accurate as those done in a sleep lab. Home sleep tests are often more convenient and less expensive too.
Myth: REM sleep is the most important sleep stage.
Truth: Each stage of sleep is important, but REM sleep, also known as rapid eye movement sleep, is essential for regulating mood, memory consolidation, and emotional processing.
Things You Need to Know
If you suspect that you have a sleep disorder, it is essential to seek diagnosis and treatment immediately. Sleep disorders are treatable, and early intervention can prevent long-term health complications.
The most common sleep disorders include sleep apnea, restless leg syndrome, insomnia, and narcolepsy.
Healthy sleep practices, such as maintaining a consistent sleep and wake schedule, unplugging electronics before bed, and minimizing caffeine and alcohol intake, can improve overall sleep quality.

Understanding the facts about sleep disorders is crucial for preventing potential health risks. Consult with your healthcare provider if you need more information or have specific concerns about your sleep.

6. Improving Your Sleep Quality: Tips for Better Sleep Hygiene

9 tips on improving sleep quality:

1. Stick to a sleep schedule: Go to bed and wake up at the same time every day, even on the weekends.
2. Create a relaxing bedtime ritual: Avoid stimulating activities, such as working or watching TV, before bed. Instead, take a warm bath, read a book or practice relaxation techniques, such as deep breathing.
3. Avoid caffeine and nicotine before bedtime: Both substances can interfere with sleep and keep you awake.
4. Create a sleep-friendly environment: Make sure your bedroom is dark, cool, and quiet, and remove any distractions, such as electronic devices.
5. Get regular exercise: Physical activity can help you fall asleep faster and sleep more soundly.
6. Avoid large meals and beverages before bedtime: Eating a heavy meal or drinking a lot of fluids can interfere with sleep.
7. Have your sleep apnea treated: Sleep apnea can severely impact your sleep quality, and treatment options are available.
8. Undergo a sleep study if necessary: If you’re experiencing persistent sleep problems or suspect a sleep disorder, a sleep study can help diagnose the issue and guide treatment.
9. Pay attention to your sleep cycles: Aim to get a full night’s sleep, including all stages of the sleep cycle, including deep wave sleep, which is crucial for physical and mental restoration.
By improving your sleep hygiene, you can promote better sleep and achieve greater overall health and well-being.

7. Decoding Your Sleep Study Report: What Do All Those Numbers Mean?

A sleep study report is an important document that provides detailed information about your sleep quality and potential sleep disorders. 
It contains a lot of numerical data that can be difficult to understand for the untrained eye. Here’s a breakdown of what all those numbers and terms mean:
Sleep Apnea Severity: If you have sleep apnea, your sleep study report will indicate the severity of your condition based on the number of apneas and hypopneas (partial obstructions) you experience per hour of sleep. This is called the Apnea-Hypopnea Index (AHI).
– For normal sleepers: AHI of 0-5
– Mild sleep apnea: AHI of 5-15
– Moderate sleep apnea: AHI of 15-30
– Severe sleep apnea: AHI of over 30.
Oxygen Saturation: This measures how much oxygen your blood is carrying while you sleep. 
A normal range is between 95-100%. Sleep apnea can cause drops in oxygen saturation levels which can be seen in the study.
Sleep Stages: During a sleep study, the different stages of sleep are measured, including REM (Rapid Eye Movement) sleep, which is the stage when most dreaming occurs.
– Awake: When there is no brain activity indicating sleep
– Light Sleep: Stage 1 and 2 sleep, when the body is starting to relax
– Deep Sleep: Stage 3 and 4 sleep, when the brain is at its most relaxed
– REM: The stage of sleep when dreaming occurs.
Latency: This is the time it takes for someone to fall asleep. This metric can help diagnose insomnia.
Sleep Efficiency: This measures the quality of sleep and is calculated as the percentage of the total time spent in bed asleep.
Overall, a sleep study report can provide valuable information about your sleep patterns and any potential sleep disorders. 
Once you receive your report, be sure to discuss any concerns or questions with your doctor at BCOH to determine the best course of treatment.

8. The Role of Sleep Medicine in Treating Sleep Disorders

Sleep medicine plays a crucial role in diagnosing and treating sleep disorders such as sleep apnea. 
Sleep apnea is a condition in which a person’s breathing becomes shallow or even stops altogether during sleep, leading to interruptions in sleep and a variety of health problems.
If sleep apnea is suspected, a sleep study may be ordered to monitor a person’s breathing and other physiological functions during sleep. This involves spending a night in a sleep lab, where electrodes are placed on the head and body to monitor brain waves, heart rate, breathing, and other sleep-related functions.
The data collected during the sleep study is analyzed by a sleep specialist, who can then make a diagnosis and recommend treatment options. 
Treatment for sleep apnea typically involves using a continuous positive airway pressure (CPAP) machine, which delivers a gentle stream of air to keep the airway open during sleep.
Other options may include oral appliances or surgery in more severe cases.
Sleep medicine also plays a role in the treatment of other sleep disorders such as insomnia, restless leg syndrome, and narcolepsy. Treatment options for these conditions may include medication, cognitive-behavioral therapy, or lifestyle changes.
Overall, the field of sleep medicine is critical in helping individuals who are affected by sleep disorders to achieve better sleep and improve their overall health and quality of life.

9. The Connection Between Sleep Apnea and Obesity: How to Break the Cycle

Sleep apnea and obesity are closely linked. Obese individuals are at a greater risk of developing sleep apnea, while individuals with sleep apnea are more likely to gain weight. This creates a vicious cycle where sleep apnea leads to weight gain, which in turn worsens sleep apnea symptoms.
To break this cycle, it is important to first identify the severity of sleep apnea through a sleep study.

A sleep study involves monitoring an individual’s sleep patterns and breathing while they sleep. 
Based on the results of the study, treatment options can be recommended.

Weight loss is one of the most effective ways to improve sleep apnea symptoms. Losing even a small amount of weight can significantly reduce the severity of symptoms. A healthy diet and regular exercise can help individuals lose weight and improve their overall health.
In addition to weight loss, there are other treatments available for sleep apnea. Continuous positive airway pressure (CPAP) machines are commonly used to treat sleep apnea. These machines deliver a steady stream of air pressure to keep the airways open during sleep.
Oral appliances and surgery may also be recommended depending on the severity of the condition. It is important to consult with a healthcare provider to determine the best treatment option for each individual.

Breaking the cycle of sleep apnea and obesity requires a commitment to lifestyle changes and seeking appropriate medical care. With proper treatment and self-care, individuals can improve their sleep apnea symptoms and overall health.

10. Treatment Options for Sleep Apnea: CPAP, Surgery, and More 

Sleep apnea is a sleep disorder that causes a person’s breathing to repeatedly stop and start during sleep, which can lead to serious health complications. 

6 Treatment options for sleep apnea include:

1. Continuous Positive Airway Pressure (CPAP) Therapy: This involves wearing a mask over the nose or mouth that delivers a constant flow of air to keep the airways open during sleep.
2. Oral Appliance Therapy: This involves wearing a custom-fitted oral appliance that repositions the jaw and tongue to keep the airway open.
3. Surgery: surgical options can include uvulopalatopharyngoplasty (UPPP), a procedure that removes excess tissue from the throat, or the insertion of implants to keep the airway open.
4. Weight Loss: Losing weight can help reduce the severity of sleep apnea by decreasing the amount of excess tissue in the throat that can block the airway.
5. Positional Therapy: Changing sleeping positions, such as sleeping on one’s side instead of the back, can help reduce the instances of apnea.
6. Dental Inventions: Such as the use of traditional bite guards or the introduction of airway promoters.
The best course of treatment will depend on factors such as the severity of the person’s sleep apnea, the cause of the disorder, and personal preferences. It is recommended that a physician should be consulted for a proper diagnosis and treatment plan. Additionally, undergoing a sleep study will determine the severity of the condition and help guide the treatment options.


Our time: 7:54am EDT
Scroll to Top