HomeLab TestsPulse Oximetry
Back to Lab Tests
Pulse Oximetry
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Lab Tests

Pulse Oximetry

Pulse oximetry is a quick, painless test that measures the oxygen saturation levels in your blood to ensure your body is functioning properly.

What is pulse oximetry?

Pulse oximetry uses a small device called a pulse oximeter to measure blood oxygen levels. When oxygen levels drop too low (a condition called hypoxemia), it can damage tissues and organs. This test provides a fast way to monitor these levels.

Why do I need pulse oximetry?

You may need this test during a routine checkup or if you have conditions such as:

  • Chronic obstructive pulmonary disease (COPD) or asthma
  • Lung cancer or heart failure
  • COVID-19
  • Sleep apnea
  • Shortness of breath

It is also used to monitor the effectiveness of lung disease medications, to check oxygen flow rates during oxygen therapy, and to monitor patients before, during, and after surgery.

What happens during the test?

A pulse oximeter is clipped to a part of your body, usually your fingertip. The device uses a special light that passes through the skin to measure oxygen saturation and heart rate. The process is painless and takes only a few seconds.

What do the results mean?

A normal oxygen saturation level typically ranges between 95% and 100%. Levels may be lower for individuals with chronic lung diseases or those living at high altitudes.

Seek immediate medical attention if:

  • Your oxygen saturation level falls to 88% or lower.
  • You experience symptoms such as bluish lips or nails, severe shortness of breath, chest pain, or a fast heart rate.

Contact your provider if your levels are 92% or lower. Note that results can be affected by dark nail polish, artificial nails, cold skin, poor circulation, or tobacco use.

Frequently Asked Questions

If you have a known chronic lung condition like COPD, your doctor may have established a specific target range for you, which might be lower than the standard 95-100%. If you do not have a chronic condition, or if this is a new drop from your baseline, contact your healthcare provider. Do not adjust your oxygen therapy dosage without medical instruction, as too much or too little oxygen can be harmful depending on your specific condition.
This often happens due to poor peripheral circulation, which can be caused by cold hands, low blood pressure, or conditions like Raynaud's phenomenon. The device relies on detecting the pulsatile flow of blood in the capillaries. Try warming your hands by rubbing them together or holding them under warm water for a minute. If the issue persists, try testing on a different finger or the earlobe, which may have better blood flow.
While a pulse oximeter can detect drops in oxygen levels (desaturation) that occur during sleep, it is not a substitute for a formal sleep study. It can serve as a useful monitoring tool to track trends or verify if your prescribed CPAP therapy is working effectively. However, it does not measure airflow or effort, which are critical for diagnosing the severity of sleep apnea. Consult your sleep specialist before relying on home oximetry for diagnostic purposes.
To get a reliable reading, remove any nail polish or artificial nails, as these can block the sensor light. Ensure your hand is warm; cold fingers restrict blood flow and can cause false low readings. Sit still for a minute before testing to stabilize your heart rate, and keep the device firmly clipped to the fingertip without moving. If the reading seems unusually low, wait a few minutes and retest on a different finger to confirm.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

kontakt@hittavard.se

Ⓒ 2024. Alla rättigheter förbehålls av juxt ab

Sök
Om ossVillkor och policyVanliga frågorKontakta oss