You Don't Need the Apple Watch Blood-Oxygen Feature, Anyway

If you were planning to buy a new Series 9 or Ultra 2, it will be missing the blood-oxygen feature. Should you care?

Apple Watches sold in the U.S. may stop being sold with blood oxygen-measuring features, according to reports that removing the feature is Apple’s response to its ongoing lawsuit with another company, Masimo. But was the feature ever all that useful in the first place? Probably not. 

Apple had previously paused sales of watches containing the blood oxygen features in late 2023. Pulse oximetry, as the technology is called, measures the saturation of oxygen in your blood. If you’ve ever used a finger-clip pulse oximeter, the Apple Watch (or one of the other smart devices with similar features) is meant to do the same thing in a more convenient format. 

Is my Apple Watch losing its blood oxygen measurements? 

If you already own a Series 6 or later watch that measures blood oxygen, it’s expected to keep running with the same functionality—so features aren’t going to be revoked in an update, as far as we are aware. Only future sales of new watches may be affected. 

Apple is still selling watches with the blood oxygen functionality, although it’s unclear whether or how soon they will be pulled from the market. If you really want an Apple watch with a blood oxygen sensor, perhaps you should buy it now.  

The lawsuit is specific to the United States, and doesn’t directly affect sales in other countries. Masimo, a maker of pulse oximeters, sued Apple in 2020 for alleged theft of its trade secrets. Ultimately the U.S. International Trade Commission sided with Masimo, ruling that Apple could no longer import watches with the feature. 

That’s what led to Apple’s pause in sales of the Series 9 and Ultra 2 in December. Shortly afterward, another court ruling allowed the company to sell the watches again while the court case proceeded. In the most recent development, Apple said it would redesign its watches to remove the blood oxygen features, and the courts agreed that the redesigned watches could be imported. (Apple has not said whether the redesign involves removing the sensors or just disabling the feature in software.)

But the court case is not over. According to AP, Apple plans to continue appealing the ruling, and to ask to be able to keep selling the oxygen-sensing watches during that process. That could mean that blood-oxygen-sensing watches stay on shelves for another year, if Apple gets its way. 

How useful is a pulse oximeter on a watch, anyway? 

Wearables companies scrambled to add blood oxygen sensing to their products after pulse oximeters became popular due to the COVID pandemic. But despite sounding fancy—another sensor is always good, right?—users haven’t gotten much actionable benefit from them. 

Here’s an informal, two-person survey: Lifehacker’s Senior Technology Editor, Jake Peterson, told me that he has the blood oxygen-sensing feature on his Apple watch, but “[hasn’t] used it much.” And if you want my take as our Senior Health Editor, I have a different wearable that detects blood oxygen (a gen 3 Oura ring), and I actually keep that feature turned off in the ring’s settings. The feature is just not useful enough to justify its slightly increased battery draw.

In short, while there are certainly Apple watch users who liked the feature and will be disappointed if it goes away, I don’t think most of us will miss it. Wearables are unlikely to ever be as accurate as hospital-style pulse oximeters, and the watches provide little to no guidance on what you should actually do with the data.

A 2023 study of accuracy in smartwatch blood oxygen sensors found that the Apple watch tested (a Series 7) was more accurate than its competitors, and that skin tone didn’t seem to affect accuracy—so that’s good news. But the study also notes that pulse oximeters tend to be less accurate when we are moving around or when skin perfusion is low (which includes times when actual blood oxygen is below 90%). These limitations could mean that you’re not actually getting an accurate reading during the times it would be most useful. 

Apple itself notes that readings are most accurate if you can do them while sitting still during the readings, with your arm flat in front of you, watch pointing up, and your hand not in a fist. They also include instructions to adjust the watch band for the best reading. Automatic background readings are possible, but they’re unlikely to be taken under these exact conditions. 

Why you probably won’t miss your blood oxygen data

Aside from accuracy, the other big question is what you do with that data. Cardiologist Nauman Mushtaq told CNET: “I don't think it, to be honest, does anything that is clinically meaningful for an average person.”

This is where the blood oxygen readings differ from some of the other data provided by a smartwatch. Your exercise heart rate, for example, can tell you whether you did as hard a workout as you were planning on, and your cardio fitness readings can give you a measure of progress as you improve your heart health and your stamina. These metrics may not always be as accurate or useful as we hope, but they can still provide some guidance since we understand what to do with them. 

But blood oxygen isn’t like that. If you see an unexpectedly low number, you would have to go to a doctor to find out if anything is actually wrong—and they’re unlikely to use smartwatch data to figure it out, anyway. If you think you may have sleep apnea, for example, you can go get tested, without needing to monitor your blood oxygen on a smartwatch first. And if your blood oxygen readings look high while you feel terrible, the readings shouldn’t stop you from seeing a doctor.