The Oura Ring can detect overall blood oxygen saturation levels, and variation in those levels, while you sleep. These measurements show how efficiently your body circulates and absorbs oxygen, making it a useful index of your overall health, as well as indicating possible disturbances in your breathing during the night.
Blood Oxygen Sensing is available for:
- Gen3 or later with active membership
- iOS
- Android
This feature is not available on Gen2 or older.
Upgrading from a Oura Ring Gen3 to a newer model may result in small changes to your readings as Oura continuously improves its hardware, sensors, and algorithms for increased accuracy.
How Does Blood Oxygen Sensing Work?
How to Use the Blood Oxygen Sensing Feature
Blood Oxygen Sensing Troubleshooting
Things to Keep in Mind
More Information
How Does Blood Oxygen Sensing (SpO2) Work?
The Oura Ring measures peripheral oxygen saturation (SpO2) levels in your blood by sending light from the ring's red and infrared LEDS into your finger while you sleep, and then measuring how much light is reflected. Richly oxygenated blood reflects more red light than infrared light, while poorly oxygenated blood reflects more infrared light than red light.
Your blood oxygen measurements are located on the Oura App's Sleep screen. The Average Blood Oxygen reading is the percentage of your blood that contains oxygen. It's measured during sleep periods longer than three hours, but the Oura App only displays the results for the longest sleep period of the day.
Please note that you may see the red LEDs light up whenever your Oura Ring detects that you may be asleep (based on your heart rate, movement, and respiratory rate), including during the day.
How to Use the Blood Oxygen Sensing (SpO2) Feature
Average Blood Oxygen is turned on by default. To toggle it on or off:
- Go to the
menu in the upper left corner of the Oura App's home screen
- Select Blood Oxygen Sensing
- Select the toggle next to Blood Oxygen Sensing
Note: Your ring must be connected to the app over Bluetooth in order to switch the feature on and off.
After your next sleep period of more than three hours, check the Sleep screen. There you will find the Average Blood Oxygen percentage.
An average between 95–100% is generally considered normal, but focus on your long-term trend rather than any single night.
Blood Oxygen Sensing (SpO2) Troubleshooting
Changes in Data
You might see Average Blood Oxygen values that are different than expected for a variety of reasons, including:
- Sleeping in a position that constrains the amount of blood flow to your hand or arm
- Having the ring in the wrong orientation
- Having a too loose or tightly fitting ring
- Excessive movement during sleep
- Other factors such as age, altitude, congestion, alcohol consumption, and overall sleep quality can all affect readings
- Upgrading from a Gen3 ring to a newer model may result in small changes to your readings as Oura continuously improves its hardware, sensors, and algorithms for increased accuracy
- Updates to Oura's algorithm may result in small differences from prior Blood Oxygen readings
Missing Data
If you are not seeing any blood oxygenation data after a sleep period of three hours or more, try the following:
- Ensure that you have the latest app software and ring firmware installed
- Charge your ring to at least 30% before going to bed
- Ensure that your ring fits snugly, and that the LED sensors are on the underside (palm-side) of your finger
- Make sure that your ring is not in Airplane Mode
- Turn on your device's Bluetooth to enable your ring to sync data with the Oura App
Things to Keep in Mind
Generally, Blood Oxygen measurement is most useful when viewed as a trend over time rather than as a single-night number. Small variations from one night to the next should be expected. Also note that readings taken at night are normally slightly lower than those taken during the day.
High variation in overnight blood oxygen measurements can be a sign that something is challenging your health, such as illness, altitude, or breathing issues.
Oura Ring is not a medical device and is not intended to diagnose, treat, cure, monitor, or prevent medical conditions or illnesses. Please do not make any changes to your medication, nutrition, or workouts without first consulting your doctor or another medical professional.
The Blood Oxygen Sensing features use the red and infrared LEDs throughout the night, which impacts your ring's overall battery life. We recommend turning on low battery notifications as a reminder.
Blood Oxygen Sensing features do not directly impact any your daily scores. However, if something is impacting the variations in Average Blood Oxygen, it may show up in the Sleep and Readiness scores already.
More Information
An Introduction to Respiratory Rate
Blood Oxygen Sensing (SpO2) on Oura
