Users upgrading to the Apple Watch Series 12 or Ultra 4 may temporarily lose access to hypertension notifications. This is because regulatory clearances are still in process for these new devices in many regions. The feature's availability is impacted in 33 countries including Canada, Australia, India, and Japan. Existing users who receive these notifications might lose the functionality upon upgrading until clearance is granted. The Series 12 and Ultra 4 feature revamped sensors and a new Health Sensing System. This includes new optical and electrical heart sensors for more frequent and accurate tracking. These hardware changes necessitate new regulatory approvals in certain locations. The new watches offer improved ECG readings, more efficient optical sensing, and enhanced heart rate measurement. Heart rates will be measured every five seconds, with real-time data available in the updated Heart Rate app. Some countries, including the United States, UK, and all EU countries, are not affected by this temporary loss.