Jay Summer Staff Writer
Jay Summer
Staff Writer
Jay Summer is a health content writer and editor. She holds a B.S. in psychology and master's degrees in writing and public policy.
Want to read more about all our experts in the field?
Dr. Abhinav Singh Sleep Medicine Physician
Dr. Abhinav Singh
Sleep Medicine Physician
Dr. Singh is the Medical Director of the Indiana Sleep Center. His research and clinical practice focuses on the entire myriad of sleep disorders.
Want to read more about all our experts in the field?
Fact-Checked
Sleep Foundation
Fact-Checking: Our Process
The Sleep Foundation editorial team is dedicated to providing content that meets the highest standards for accuracy and objectivity. Our editors and medical experts rigorously evaluate every article and guide to ensure the information is factual, up-to-date, and free of bias.
The Sleep Foundation fact-checking guidelines are as follows:
- We only cite reputable sources when researching our guides and articles. These include peer-reviewed journals, government reports, academic and medical associations, and interviews with credentialed medical experts and practitioners.
- All scientific data and information must be backed up by at least one reputable source. Each guide and article includes a comprehensive bibliography with full citations and links to the original sources.
- Some guides and articles feature links to other relevant Sleep Foundation pages. These internal links are intended to improve ease of navigation across the site, and are never used as original sources for scientific data or information.
- A member of our medical expert team provides a final review of the content and sources cited for every guide, article, and product review concerning medical- and health-related topics. Inaccurate or unverifiable information will be removed prior to publication.
- Plagiarism is never tolerated. Writers and editors caught stealing content or improperly citing sources are immediately terminated, and we will work to rectify the situation with the original publisher(s)
- Although Sleep Foundation maintains affiliate partnerships with brands and e-commerce portals, these relationships never have any bearing on our product reviews or recommendations. Read our full Advertising Disclosure for more information.
Up-to-Date
Table of Contents
Table of Contents
- What Do Blood Oxygen Level Readings Mean?
- How Low Can Your Oxygen Levels Go During Sleep?
- What Is a Dangerously Low Oxygen Level While Sleeping?
- When to Seek Help for Low Oxygen Levels While Sleeping
Key Takeaways
- Normal oxygen levels during sleep range from 96% to 100%.
- Sleep apnea and respiratory disorders can impact oxygen saturation.
- Monitor and address any chest pain, shortness of breath, and concerning symptoms.
Blood oxygen levels help show whether a person has enough oxygen Trusted Source UpToDateMore than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights.View Source in their body. Among health experts, there is no consensus on a universal definition of a normal blood oxygen level. However, blood oxygen levels at or below 88% Trusted Source UpToDateMore than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights.View Source for five or more minutes during sleep may be a sign of a sleep-related breathing disorder.
Doctors may recommend that people with sleep apnea, lung disease, or other breathing difficulties check their blood oxygen levels. We review what people monitoring their levels overnight should know about factors that affect blood oxygen levels, reasons why these levels may drop during sleep, and when to seek medical help.
What Do Blood Oxygen Level Readings Mean?
Blood oxygen levels measure the percentage of a person’s red blood cells that carry oxygen, which is sometimes called oxygen saturation Trusted Source Medline PlusMedlinePlus is an online health information resource for patients and their families and friends.View Source . Oxygen saturation reflects how effectively the lungs are taking in oxygen and delivering it into the bloodstream.
Doctors and nurses usually measure blood oxygen levels using a pulse oximeter Trusted Source Merck ManualFirst published in 1899 as a small reference book for physicians and pharmacists, the Manual grew in size and scope to become one of the most widely used comprehensive medical resources for professionals and consumers.View Source . A pulse oximeter is a small, painless clip typically placed on a person’s fingertip. When pulse oximeters are worn over a prolonged period, such as during sleep, they can record blood oxygen levels continuously over time.
A blood gas test is another way of measuring blood oxygen levels. Although generally more accurate, blood gas tests require a blood draw, can’t be performed at home, and only measure levels at a single point in time. For that reason, pulse oximeters and other sleep trackers are better suited for at-home monitoring of blood oxygen levels during sleep.
Blood oxygen levels can vary slightly during sleep. For example, oxygen saturation levels may show a minor increase or decrease with changes in sleeping position Trusted Source National Library of Medicine, Biotech InformationThe National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information.View Source . Blood oxygen levels may be slightly lower, but still within normal ranges, while a person lies on their back compared with when they lie on their stomach.
“Low oxygen levels typically represent a secondary problem and should be investigated. Convenient tests are available and should be used in conjunction with a doctor’s evaluation.”
Dr. Abhinav Singh, Sleep Physician
How Low Can Your Oxygen Levels Go During Sleep?
Many factors influence the interpretation of oxygen levels, so there is no universal standard for normal oxygen levels. That said, blood oxygen levels above 95% are normal for most people. In certain circ*mstances, though, blood oxygen levels above 95% may be too high Trusted Source UpToDateMore than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights.View Source , such as in some people with chronic obstructive pulmonary disease (COPD).
People monitoring their blood oxygen levels at home should make note of any unexplained changes to their usual levels, even if their oxygen saturation stays above 95%. Blood oxygen levels usually only change by about one percentage point each hour Trusted Source National Library of Medicine, Biotech InformationThe National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information.View Source , so people should talk to their doctors about larger drops.
Oxygen saturation at or below 92% is too low for most people. However, levels between 89 to 92% may be expected for some people with chronic lung disease. Anyone who is monitoring their blood oxygen levels should talk to their doctor about the right level for them and what level should be considered too low.
People should get medical care as soon as possible if their blood oxygen levels drop to or below 88%.
Blood Oxygen Level | Interpretation |
---|---|
96 to 100% | Normal range |
93 to 95% | Borderline low |
89 to 92% | Low |
88% or lower | Dangerously low |
Some people regularly have lower blood oxygen levels during sleep. For example, people living at high altitudes may have lower-than-average oxygen saturation. People with COPD or other chronic lung diseases also typically have lower blood oxygen levels Trusted Source American Academy of Sleep Medicine (AASM)AASM sets standards and promotes excellence in sleep medicine health care, education, and research.View Source during sleep. In addition, some people with disorders of the chest muscles or nerves may have chronically low Trusted Source UpToDateMore than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights.View Source blood oxygen levels at night.
What Is a Dangerously Low Oxygen Level While Sleeping?
Blood oxygen levels at or below 88% are considered dangerously low for most people. When a person’s blood oxygen levels drop too low Trusted Source UpToDateMore than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights.View Source , their vital organs may not get enough oxygen.
Sleep-related hypoxemia is a disorder involving blood oxygen levels that fall to 88% or below for at least five minutes during sleep without hypoventilation or another sleep-related breathing disorder. In children, drops in oxygen saturation to 90% or below for five minutes or more may also meet the criteria for sleep-related hypoxemia.
Sleep-related hypoxemia is typically caused by another health condition. A variety of medical issues have been linked to sleep-related hypoxemia, including COPD, sickle cell disease, and pneumonia.
Obstructive and central sleep apnea can also cause drops in blood oxygen levels while sleeping. However, oxygen saturation usually only drops for less than a minute at a time in these conditions, while reduced levels in sleep-related hypoxemia usually last for several minutes.
Opioid painkillers, alcohol, sleeping pills, and certain anxiety drugs may be linked to both lower blood oxygen levels and slowed breathing during sleep. People with sleep-related breathing disorders, heart disease, or lung disorders should be cautious and talk with their doctor before taking these substances.
When to Seek Help for Low Oxygen Levels While Sleeping
People should contact a health care provider if their blood oxygen levels drop below 93%, and they should seek prompt medical care if levels are below 88%. It is also important to seek medical attention when experiencing symptoms of a lack of oxygen, including:
- Shortness of breath
- Chest pain
- Rapid heartbeat
- Blue nail beds, lips, or face
Some people may not have symptoms despite having low oxygen levels during sleep, or they may experience only general feelings of fatigue or unrefreshing sleep.
Sudden, severe drops in blood oxygen levels can be a medical emergency. A repeated lack of oxygen delivered to vital organs can increase the risk of serious medical conditions, including stroke and heart failure.
Promptly seeing a doctor about low oxygen levels can allow the doctor to provide supplemental oxygen if it is needed, investigate the underlying cause, and start appropriate treatment.
Medical Disclaimer: The content on this page should not be taken as medical advice or used as a recommendation for any specific treatment or medication. Always consult your doctor before taking a new medication or changing your current treatment.
Written By
Jay Summer,Staff Writer
Jay Summer is a health content writer and editor. She holds a B.S. in psychology and master's degrees in writing and public policy.
Medically Reviewed by
Dr. Abhinav Singh,Sleep Medicine PhysicianMD
Dr. Singh is the Medical Director of the Indiana Sleep Center. His research and clinical practice focuses on the entire myriad of sleep disorders.
References
10 Sources
Mechem, C. (2022, March 4). Pulse oximetry. In P. Parsons (Ed.). UpToDate., Retrieved May 2, 2023, from
https://www.uptodate.com/contents/pulse-oximetryBadr, M. (2022, September 6). Sleep-related breathing disorders in COPD. In U. Hatipoglu (Ed.). UpToDate., Retrieved May 2, 2023, from
https://www.uptodate.com/contents/sleep-related-breathing-disorders-in-copdA.D.A.M. Medical Encyclopedia. (2021, July 27). Pulse oximetry. MedlinePlus., Retrieved May 2, 2023, from
https://medlineplus.gov/lab-tests/pulse-oximetry/Dezube, R. (2022, September). Arterial blood gas (AGB) analysis and pulse oximetry. Merck Manual Consumer Version., Retrieved May 2, 2023, from
https://www.merckmanuals.com/home/lung-and-airway-disorders/diagnosis-of-lung-disorders/arterial-blood-gas-abg-analysis-and-pulse-oximetryCeylan, B., Khorshid, L., Güneş, Ü. Y., & Zaybak, A. (2016). Evaluation of oxygen saturation values in different body positions in healthy individuals. Journal of clinical nursing, 25(7-8), 1095–1100.
https://pubmed.ncbi.nlm.nih.gov/26879626/Carter, R. & Nwasuruba, C. (2022, December 7). Long-term supplemental oxygen therapy. In J. Stoller (Ed.). UpToDate., Retrieved May 4, 2023, from
https://www.uptodate.com/contents/long-term-supplemental-oxygen-therapyBhogal, A. S., & Mani, A. R. (2017). Pattern Analysis of Oxygen Saturation Variability in Healthy Individuals: Entropy of Pulse Oximetry Signals Carries Information about Mean Oxygen Saturation. Frontiers in physiology, 8, 555
https://pubmed.ncbi.nlm.nih.gov/28824451/American Academy of Sleep Medicine. (2014). The International Classification of Sleep Disorders – Third Edition (ICSD-3). Darien, IL.
https://aasm.org/Kramer, N., Millman, R., & Hill, N. (2022, May 12). Evaluation of sleep-disordered breathing in patients with neuromuscular and chest wall disease. In G. Finlay (Ed.). UpToDate., Retrieved May 4, 2023, from
https://www.uptodate.com/contents/evaluation-of-sleep-disordered-breathing-in-patients-with-neuromuscular-and-chest-wall-diseaseTheodore, A. (2022, November 22). Measures of oxygenation and mechanisms of hypoxemia. In P. Parsons (Ed.). UpToDate., Retrieved May 2, 2023, from
https://www.uptodate.com/contents/measures-of-oxygenation-and-mechanisms-of-hypoxemia
Learn More About Physical Health and Sleep
Morning Headaches: Why Do I Wake Up With A Headache?
ByJay Summer March 12, 2024
Thyroid Issues and Sleep
ByDanielle Pacheco March 8, 2024
Waking Up with Back Pain: Causes and Tips for Relief
ByJay Summer February 29, 2024
The Relationship Between Sex and Sleep
ByEric Suni February 14, 2024
Physical Health and Sleep
ByJay Summer February 9, 2024
Farting During Sleep: Causes and Tips for Reducing It
ByDanielle Pacheco January 23, 2024
Nosebleeds While Sleeping
ByJay Summer January 23, 2024
Sciatic Nerve Pain Relief at Night
ByDanielle Pacheco January 23, 2024
How to Sleep With a Cough or a Cold
ByJay Summer January 22, 2024
Epilepsy and Sleep: Understanding the Relationship
ByJay Summer January 19, 2024
Numbness in Hands While Sleeping: Causes and Remedies
ByLucy Bryan January 18, 2024
What Is a Normal Sleeping Heart Rate?
ByJay Summer January 18, 2024
Leg Cramps at Night: Tips to Reduce Discomfort
ByJay Summer January 16, 2024
Cataplexy
ByRob Newsom January 16, 2024
The Relationship Between Anemia and Sleep
ByJay Summer January 5, 2024
Painsomnia
ByJay Summer December 22, 2023
Excessive Yawning: What Does It Mean and How to Treat It
ByJay Summer December 22, 2023
Parkinson's Disease and Sleep
ByDanielle Pacheco December 22, 2023
Why You Shouldn't Sleep With Contacts In
ByDanielle Pacheco December 22, 2023
Sleeping With Your Eyes Open
ByJay Summer December 22, 2023
Why Intermittent Fasting Can Lead to Better Sleep
ByJay Summer December 22, 2023
Weight Loss and Sleep
ByRob Newsom December 22, 2023
Can a Lack of Sleep Cause Nausea?
ByJay Summer December 22, 2023
Is It Safe To Sleep If You Have a Concussion?
ByDanielle Pacheco December 22, 2023
How Sleep Apnea Affects Blood Pressure
ByAlexa Fry December 22, 2023
Dry Mouth At Night: What Causes It and How to Prevent It
ByJay Summer December 22, 2023
Fibromyalgia and Sleep
ByDanielle Pacheco December 22, 2023
Obesity and Sleep
ByAlexa Fry December 22, 2023
Sleep and Overeating
ByEric Suni December 22, 2023
Allergies and Sleep
ByDanielle Pacheco December 21, 2023
Migraines and Sleep: A Bidirectional Relationship
ByJay Summer December 15, 2023
Heart Palpitations at Night: Diagnosis and Treatment
ByJay Summer December 7, 2023
Rest and Recovery: How to Sleep With Intercostal Muscle Strain
ByDanielle Pacheco November 22, 2023
Waking Up Gasping for Air: Exploring Causes and Treatment
ByJay Summer November 22, 2023
Waking Up With a Dry Throat: What Causes It and How Do You Treat It?
ByDanielle Pacheco November 22, 2023
What Causes Night Sweats in Men?
ByTom Ryan, PhD November 22, 2023
GERD and Sleep
ByEric Suni November 22, 2023
How to Sleep with Lower Back Pain: Finding Comfort and Relief
ByEric Suni November 22, 2023
Medical and Brain Conditions That Cause Excessive Sleepiness
ByEric Suni November 22, 2023
Nocturia: Causes and Treatments for Frequent Urination
ByEric Suni November 22, 2023
Progesterone for Sleep: Everything You Need to Know
ByLucy Bryan November 17, 2023
Nicotine and Sleep
ByRob Newsom November 1, 2023
Alzheimer’s Disease and Sleep
ByAlexa Fry October 31, 2023
How Sleep Deprivation Affects Your Heart
ByEric Suni October 30, 2023
Sleep and Blood Glucose Levels
ByDanielle Pacheco October 26, 2023
Lack of Sleep and Diabetes
ByDanielle Pacheco October 26, 2023
How Does Testosterone Affect Sleep?
ByEric Suni October 20, 2023
How To Sleep with Tinnitus
ByJay Summer October 18, 2023
How Sleep Affects Immunity
ByEric Suni August 15, 2023
Why Does My Body Ache When I Wake Up?
ByJay Summer July 14, 2023
Vertigo While Sleeping: Tips and Treatment
ByJay Summer June 28, 2023
Autism and Sleep
ByJay Summer June 22, 2023
Sleep Apnea and Heart Disease
ByRob Newsom June 15, 2023
How to Sleep With a Sore Throat
ByJay Summer June 6, 2023
Pain and Sleep
ByDanielle Pacheco May 23, 2023
Memory and Sleep
ByDanielle Pacheco April 28, 2023
Diet, Exercise, and Sleep
ByRob Newsom March 3, 2023
Cancer and Sleep
ByEric Suni February 23, 2023
Can a Lack of Sleep Cause Headaches?
ByDanielle Pacheco February 13, 2023
Smith-Magenis Syndrome and Sleep
ByRob Newsom January 19, 2023
Beauty Sleep
ByYazan Hamzeh January 6, 2023
Multiple Sclerosis (MS) and Sleep
ByDanielle Pacheco April 20, 2022
Load More Articles
Other Articles of Interest
Physical Activity and Sleep
Sleep Disorders
How Sleep Works
Sleep Hygiene
Back
We Are Here To Help You Sleep.
Tell us about your sleep by taking this brief quiz.
Based on your answers, we will calculate your freeSleep Foundation Score™and create a personalized sleep profile that includes sleep-improving products and education curated justfor you.