Can the Fitbit Versa 4 measure blood oxygen levels during sleep

Fitbit devices, including the Versa series, use red and infrared sensors on the back of the device to estimate oxygen variation. These sensors shine light onto the skin and blood vessels, using the reflected light to approximate how much oxygen is in the blood. Richly oxygenated blood reflects more red light, while poorly oxygenated blood reflects more infrared light[7].

To view EOV data, users must wear their Fitbit to bed and sync the device in the morning. The data can be accessed through the Fitbit app by tapping on the Sleep duration tile and then selecting estimated oxygen variation. The graph will show variations in estimated blood oxygen saturation levels throughout the night. Low variations indicate consistent oxygen levels, while high variations may suggest breathing disturbances[7].

It's important to note that while the Fitbit Versa 4 can provide insights into oxygen variation during sleep, it does not directly display SpO2 levels. However, Fitbit has released features and watch faces for other models that allow users to view SpO2 data, such as the SpO2 Signature clock face available for the Versa and Ionic lines[3].

For accurate EOV readings, it's crucial to ensure the device is snug and secure on the wrist and that the user sleeps for at least three hours[7]. If frequent high variations are observed, it may be advisable to consult a healthcare professional, especially if accompanied by symptoms like excessive tiredness or snoring[7].