what is spo2 in smartwatch

SpO2 in smartwatches stands for "Blood Oxygen Saturation Level". It is a measure of the amount of oxygen present in the hemoglobin in your blood. SpO2 sensors in smartwatches work similarly to the photoplethysmography (PPG) sensors used to measure heart rate. PPG sensors work by shining a green light into your skin to determine your heart rate based on the light that’s reflected back. The difference is that, instead of green light, smartwatch SpO2 sensors shine red and infrared light into your skin. Then, based on the way light reflects back, the devices use an algorithm to estimate your blood oxygen levels. SpO2 monitoring is now a standard feature in many smartwatches and fitness trackers. However, it is worth noting that the SpO2 monitor in smartwatches has no medical accreditation, indicating that it is not intended for diagnosis or wellness. The findings are usually inaccurate, and the feature is more for fitness purposes.