Blood Oxygen Sensing (SpO2)

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 not available for Gen2 and older.

How Does Blood Oxygen Sensing Work?
How to Use the Blood Oxygen Sensing Features
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. The Breathing Regularity graph displays variations in how much oxygen is present in your blood. This is different from respiratory rate, which measures how many breaths per minute (BPM) you take. Average Blood Oxygen and Breathing Regularity are 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) Features

Average Blood Oxygen and Breathing Regularity are turned on by default. To toggle them 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 and Breathing Regularity display.

Suspected variations in your blood oxygen levels are shown in a color-coded timeline, indicating sampling intervals of 15 minutes.

Optimal: no significant variations to display
Good: few variations detected (dark blue line)
Fair: occasional variations detected (light blue line)
Pay attention: frequent variations detected (white line)

If your blood oxygen levels are measured as "Optimal" throughout the night, the Oura App will not display a Breathing Regularity timeline. Tap on the information ⓘ icon in the app to learn more about Breathing Regularity, how to improve it, and how to interpret the displayed information.

Blood Oxygen Sensing (SpO2) Troubleshooting

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

High variation in overnight blood oxygen measurements can be a sign that something is challenging your health, such as illness, altitude, or breathing issues.

The 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 Breathing Regularity and Average Blood Oxygen, it may show up in the Sleep and Readiness scores already.