What is blood oxygen
Your blood oxygen level represents the percentage of oxygen your red blood cells carry from your lungs to the rest of your body.
Knowing how well your blood performs this key task can help you understand your overall wellness.
The majority of people have a blood oxygen level of 95 – 100%. However, some people live a normal life with blood oxygen levels below 95%. Slightly lower values while sleeping are expected, and some users might experience values below 95%.
How to use the Blood Oxygen app
follow the steps to set up the Blood Oxygen app.
Here’s what you need
- Make sure that the Blood Oxygen app is available in your country or region. You will be able to see this during the setup process.
- Update your iPhone 6s or later to the latest version of iOS.
- Update your Apple Watch Series 6 to the latest version of watchOS.
- The Blood Oxygen app is not available for use by people under 18 years old. You can confirm or set up your age in your Health Profile.
Note-The Blood Oxygen app is not available if you set up your Apple Watch with Family Setup.
Set up the Blood Oxygen app and background readings
- On your iPhone, open the Health app.
- Follow the onscreen steps. If you don’t see a prompt to set up, tap the Browse tab, then tap Respiratory > Blood Oxygen > Set up Blood Oxygen.
- After you complete setup, open the Blood Oxygen app on your Apple Watch to measure your blood oxygen levels.
How to take a blood oxygen measurement
You can take a blood oxygen measurement at any time with the Blood Oxygen app.
- Make sure that your Apple Watch is snug but comfortable on your wrist.
- Open the Blood Oxygen app on your Apple Watch.
- Stay still, and make sure your wrist is flat with the Apple Watch facing up.
- Tap Start, then keep your arm steady for 15 seconds.
- Wait. The measurement takes 15 seconds. At the end of the measurement, you will receive the results.
- Tap Done.
How to get the best results
- Rest your arms on a table or in your lap while you take a measurement. Keep your wrist and palm down and flat, and hold as still as you can.
- Make sure that your Apple Watch isn’t loose on your wrist. The band should be snug but comfortable, and the back of your Apple Watch needs to be touching your wrist.
- Make sure that the back of your Apple Watch is flush with the top of your wrist. If your wrist bones interfere with this, move your watch 1 to 2 inches up your arm away from your wrist bone.
How the Blood Oxygen app works
In Apple Watch Series 6, the optical heart sensor has been redesigned to add blood oxygen measurement capabilities. During a blood oxygen measurement, the back crystal shines red and green LEDs and infrared light onto your wrist. Photodiodes then measure the amount of light reflected back.
Advanced algorithms use this data to calculate the color of your blood. The color determines your blood oxygen level — bright red blood has more oxygen, while dark red blood has less.
View your Health information
All blood oxygen measurements, whether on-demand or inhe background, are saved in the Health app on your iPhone.
- Open the Health app.
- Tap the Browse tab, then tap Respiratory > Blood Oxygen.
You can also filter and view measurements taken only while sleeping