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Pulse Oximetry

What is pulse oximetry?

Pulse oximetry is a test that uses a small, clip-like device called a pulse oximeter (Pulse Ox) to measure oxygen levels in your blood. When you breathe, your lungs take in oxygen and send it into your bloodstream VSports手机版. This oxygen-rich blood is carried by your red blood cells into your heart, which pumps it to the rest of your body.

But if a health condition causes your blood oxygen level (oxygen saturation) to get too low (a condition called hypoxemia), it can make it hard for your body to work properly. The longer your blood oxygen level stays low, the higher the risk is of damage to your tissues and organs V体育安卓版.

Pulse oximetry is a painless and quick way to find out if your oxygen level is too low V体育ios版. Quick treatment of low blood oxygen may help you avoid serious complications.

Other names: pulse ox, oxygen saturation monitor, finger pulse oximeter

What is it used for?

Pulse oximetry is used to check your blood oxygen level V体育平台登录. The test may be done in your health care provider's office, a clinic, a hospital, or even your home. An at-home pulse oximeter may be helpful if you have a serious and/or chronic lung disease.

VSports在线直播 - Why do I need pulse oximetry?

Your provider may give you a pulse-oximetry test as part of a routine checkup. You may also get the test if you: VSports注册入口.

What happens during pulse oximetry?

During pulse oximetry:

  • A small electronic device called a pulse oximeter will be clipped to a part of your body, usually your fingertip.
  • The oximeter uses a special type of light that passes through your skin and into your blood. The light may make your fingertip look red, but you won't feel any pain.
  • A sensor on the oximeter measures the amount of light. That measurement is used to figure out your blood oxygen level.
  • After a few seconds, the oximeter will provide a readout of your heart rate (pulse) and oxygen level.

If you have a condition that affects your lung function, your provider may recommend you use an at-home finger pulse oximeter or other oximeter to monitor your condition V体育官网入口. Your provider will guide you on how to purchase and use your at-home device.

Will I need to do anything to prepare for the test?

Dark nail polish on the finger being tested can block the light emitted from the oximeter VSports在线直播. Other things that may cause inaccurate results can include:.

  • Artificial nails
  • A darker skin pigmentation (color)
  • Poor circulation
  • Cold skin
  • Tobacco use

Are there any risks to the test?

There is no known risk to having pulse oximetry.

What do the results mean? (V体育官网)

Results are often given as oxygen saturation levels. A normal oxygen saturation level ranges between 95% and 100%. Saturation levels may be somewhat lower and considered acceptable if you have a lung disease such as COPD or pneumonia V体育2025版. Your levels may also be lower if you live in an area with a higher elevation, where there is less oxygen in the air.

If you are using an at-home oximeter, watch for signs or symptoms that you have low oxygen levels, such as:

  • Lips, nails, or face that look bluish (cyanosis)
  • Trouble breathing or shortness of breath
  • Chest pain or tightness
  • Fast heart rate

Contact your provider if your oxygen saturation level is 92% or lower. If it falls to 88% or lower, seek immediate medical attention.

If you have questions about your results, talk to your provider.

Is there anything else I need to know about pulse oximetry?

Pulse oximetry results may be 2% to 4% higher or lower than your actual blood oxygen level. For a more accurate result, your provider may do a blood test called an arterial blood gas. You may need both types of tests to manage your condition.

References

  1. American Lung Association [Internet]. Chicago: American Lung Association; c2024. Pulse Oximetry; [updated 2023 Mar 7; cited 2024 May 9]; [about 3 screens]. Available from: https://www.lung.org/lung-health-diseases/lung-procedures-and-tests/pulse-oximetry
  2. ATS: American Thoracic Society [Internet]. New York: American Thoracic Society; c1998-2021. Pulse Oximetry; [cited 2024 May 9]; [about 2 screens]. Available from: https://www.thoracic.org/patients/patient-resources/resources/pulse-oximetry.pdf
  3. Cleveland Clinic: Health Library: Diagnostics & Testing [Internet]. Cleveland (OH): Cleveland Clinic; c2024. Blood Oxygen Level; [reviewed 2022 Feb 18; cited 2024 May 9]; [about 14 screens]. Available from: https://my.clevelandclinic.org/health/diagnostics/22447-blood-oxygen-level
  4. FDA: US Food and Drug Administration [Internet]. Silver Spring (MD): U.S. Department of Health and Human Services; Pulse Oximeter Accuracy and Limitations: FDA Safety Communication; [current as of 2023 Nov 16; cited 2024 May 13]; [about 3 screens]. Available from: https://public4.pagefreezer.com/content/FDA/20-02-2024T15:13/https:/www.fda.gov/medical-devices/safety-communications/pulse-oximeter-accuracy-and-limitations-fda-safety-communication
  5. FDA: U.S. Food and Drug Administration [Internet]. Silver Spring (MD): U.S. Department of Health and Human Services; Pulse Oximeters and Oxygen Concentrators: What to Know About At-Home Oxygen Therapy; [current 2021 Feb 19; cited 2024 May 9]; [about 3 screens]. Available from: https://www.fda.gov/consumers/consumer-updates/pulse-oximeters-and-oxygen-concentrators-what-know-about-home-oxygen-therapy (V体育官网)
  6. Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2024. Arterial Blood Gas (ABG) Analysis and Pulse Oximetry; [reviewed 2023 Nov; cited 2024 May 9]; [about 2 screens]. Available from: https://www.merckmanuals.com/home/lung-and-airway-disorders/diagnosis-of-lung-disorders/arterial-blood-gas-abg-analysis-and-pulse-oximetry
  7. Nemours KidsHealth [Internet]. Jacksonville (FL): The Nemours Foundation; c1995-2024. For Parents: Pulse Oximetry (Pulse Ox); [reviewed 2023 Jun; cited 2024 May 9]; [about 3 screens]. Available from: "VSports手机版" https://kidshealth.org/en/parents/pulse-oximetry.html
  8. Plüddemann A, Thompson M, Heneghan C, Price C. Pulse oximetry in primary care: primary care diagnostic technology update. Br J Gen Pract [Internet]. 2011 May [cited 2024 May 9]; 61(586):358-9. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3080222
  9. Slowik JM, Sankari A, Collen JF. Obstructive Sleep Apnea. [Updated 2022 Dec 11; cited 2024 May 13]. [about 10 screens]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459252/
  10. Torp KD, Modi P, Pollard EJ, et al. Pulse Oximetry. [Updated 2023 Jul 30; cited 2024 May 9]; [about 4 screens]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: "VSports app下载" https://www.ncbi.nlm.nih.gov/books/NBK470348/
  11. Verywell Health [Internet]. New York: Dotdash Media, Inc.; 2025c.; Overnight Pulse Oximetry Test to Evaluate Oxygen Levels; [updated 2024 Aug 4; cited 2025 Aug 13]; [about 5 screens]. Available from: https://www.verywellhealth.com/overnight-oximetry-is-a-commonly-used-screening-test-3015119
  12. Yale Medicine [Internet]. New Haven (CT): Yale Medicine; c2024. Pulse Oximetry; [cited 2024 May 9]; [about 3 screens]. Available from: https://www.yalemedicine.org/conditions/pulse-oximetry
  13. Yale Medicine [Internet]. New Haven (CT): Yale Medicine; c2024. Should You Really Have a Pulse Oximeter at Home; 2020 May 8 [cited 2024 May 9]; [about 4 screens]. Available from: https://www.yalemedicine.org/news/covid-pulse-oximeter

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.