Blood Oxygen not available on Apple Watch Ultra 2 after watchOS 18.6.1 update

KiltedTim wrote:

That screen shot is not accurate. Blood oxygen results are not visible on the watch. They will only be visible in the health app on the phone.

A clarification to the correction: the reading will not be visible on Watch with the Watch models ending LW/A. The display is only on iPhone.

With Watch models ending LL/A, the pulse oximetry display remains on Watch.

Well I feel silly! Apparently, because it wasn’t available. I had deleted the app from my watch. It was in the cloud! Re-downloaded it and now it is available. You will get a reading if you do the ECG. But results only show in the health app.

I did all the updates and still couldn't get O2 measurement until I ran the EKG. Of course this is ridiculous since it's not mentioned anywhere to do this. With as much as apple software engineers get paid they could do a LOT better

Thank you. After running the ECG, the Blood oxygen is now working.

Same here. Do an ECG reading, then use the Blood Oxygen app to take a reading. It works.

A reboot of the both devices didn't work but after taking a ECG reading the blood oxygen app works.

Thanks for posting, I tried it, did an ECG with my Ultra 2, and then the O2 app started working.

The Blood Oxygen app is available on Apple Watch Series 6 and later, including Apple Watch SE (2022), Apple Watch Ultra, and Apple Watch Ultra 2. It is not supported on earlier models such as Series 5, Series 4, or the original Apple Watch SE. If you have a compatible model and still cannot use the feature after updating, you may be affected by the bug described below.

How to fix Blood Oxygen not working on watchOS 11.6.1

Zollo’s method uses other health sensors on the Apple Watch to “wake” the Blood Oxygen function:

• Open the Heart Rate app on your Apple Watch.
• Take a manual heart rate reading.
• Open the ECG app.
• Perform a full ECG reading.

After completing these steps, the Blood Oxygen app may reappear as active, allowing you to take measurements normally.

Why this Blood Oxygen fix might work

The exact reason this sequence works is unclear, but it likely forces watchOS to refresh sensor permissions and availability, triggering the Blood Oxygen feature to become accessible again.

I also had the same issue but read if you run the ECG the. The blood oxygen will work so I tried it and it does work!

DeanMBP wrote:

Yes, I had updated both before it posted the original post. I don’t see any change at all.

If you are looking in the Respiratory section of Health app on the iPhone — Health app on the iPhone, and not on Watch — and are running iOS 18.6.1 and watchOS 11.6.1, then contact Apple. There is no display on the Watch.

DeanMBP wrote:

Looks like I’ll have to give Apple a shot. I’ve done all of that. Looked in the health app and the respiratory section, it shows my old data, but nothing new. How do you trigger a new reading?

Opening the Respiratory section of Health on the paired iPhone should be enough.

I’d try an un-pair and re-pair, as that’ll probably be at the top of the Apple troubleshooting when you call them.

For US-imported Ultra 2 with model numbers ending with LL/A, the app and sensor are available on the Watch, and continue to function as they have.

For US-imported Ultra 2 model numbers ending with LW/A and with iOS 18.6.1 and watchOS 11.6.1, the pulse oximeter function is now in the iPhone, in the Respiratory part of Health app.

Identify your Apple Watch - Apple Support

Apple Watch models sold in other countries and regions are not affected by this, and the pulse oximetry feature and app remain available in the Watch.

That screen shot is not accurate. Blood oxygen results are not visible on the watch. They will only be visible in the health app on the phone.

DeanMBP wrote:

Hmmmmm .... I bought my Ultra 2 (in the US) AFTER it had been disabled. Mine ends in LW/A. Can I take a manual reading from the health app?

I’m concerned. Confusion can be one of the signs of hypoxia. 😉

As for your question, did you update iOS and watchOS, and try it?