Huawei Watch blood oxygen saturation (SpO2) measuring feature

Blood oxygen saturation (SpO2) is a feature in the latest Huawei and Honor smart watches.

Image from Huawei's website

This feature is available in the Huawei Watch GT2 sold in China, but had somehow been disabled in that model sold in the international market. Anyhow, this feature has now been enabled to Huawei Watch GT2 sold outside China as well, following its firmware update version 1.0.6.26 and above (latest firmware version as of now should be 1.0.6.32).

SpO2 represents an estimation of oxygen levels in a person’s bloodstream. According to description in Huawei's website, "blood oxygen saturation (SpO2) is one of the important vital signs that can reflect the oxygen supply of the body. Very low levels of SpO2 can result in serious symptoms such as lack of energy, fatigue and light-headedness."

Under normal conditions, a healthy person should have an SpO2 level between 90 and 100.

The heart of an average adult normally pumps about 5,000 ml of blood per minute to the tissues and organs of the body, delivering about 1,000 ml of oxygen per minute to the body. Body function will be affected if the oxygen is at low level, causing hypoxemia and even hypoxia problem.

There are 2 types of hypoxemia. Acute hypoxemia occurs over a relatively short period of time, while chronic hypoxemia is ongoing over a longer period.

Common symptoms of acute hypoxemia include: shortness of breath, rapid breathing, wheezing, cough, confusion, headache, fast heart rate, and bluish colour in skin, fingernails and/or lips.

Common symptoms of chronic hypoxemia include: pulmonary hypertension, cor pulmonale (enlargement of right-side of the heart), heart failure, and polycythemia.

People who are having a higher risk of hypoxemia should regularly check their SpO2 level. You are one of them if you are:

• always on a busy work schedule
• working or living in a stressful environment
• working in a situation that needs to use a lot of brain everyday
• located in a place of high-altitude (with low atmospheric pressure)
• elderly people (with decreased body function)
• snoring a lot or having sleep apnea problem (might cause respiratory obstruction)
• having heart defects
• having lung conditions, including asthma, emphysema, bronchitis, corona virus infection, etc.

Huawei SpO2 sensor technology makes it easy to measure SpO2 level, anytime, at any place. Clinically, SpO2 level is measured using arterial blood gas (ABG) test, pulse oximeter, etc.

To measure SpO2 with a Huawei / Honor watch or band that supports the feature, just keep your arm still, fasten the strap tightly, and make sure the screen is facing up. Then, swipe on the screen for the SpO2 function, and start your measurement. It will take about 1 minute to complete.