Red and green light on Apple Watch
What does it mean if red and green light are both lit at the same time on Apple Watch
User profile for user:
Chris_D13
User level:
Community Specialist
Hey there taimour699,
The LED lights are used to help with detecting heart rate and blood flow. Check out those details in the article below:
Monitor your heart rate with Apple Watch - Apple Support
Apple Watch uses green LED lights paired with light‑sensitive photodiodes to detect the amount of blood flowing through your wrist at any given moment. When your heart beats, the blood flow in your wrist — and the green light absorption — is greater. Between beats, it’s less. By flashing its LED lights hundreds of times per second, Apple Watch can calculate the number of times the heart beats each minute — your heart rate.
The optical heart sensor can also use infrared light. This mode is what Apple Watch uses when it measures your heart rate in the background, and for heart rate notifications. Apple Watch uses green LED lights to measure your heart rate during workouts and Breathe sessions, and to calculate walking average and Heart Rate Variability (HRV).
Take care!