Yes, it can happen. The reasons may vary, and the following are two of the ways data can be deleted:

1. Data was not uploaded to the App for too long:
Generally, 3-5 days of data can be stored in BioSense, depending on the amount of personal data collected per day, which includes health data. If this data is not synced before memory is full, old data will be overwritten by new data, meaning the overwritten old data is deleted). The App will not be able to sync old, overwritten data.

2. BioSense Reset:
Resetting the Band may result in the deletion of all data recorded by BioSense if the device was not synced with the Helo Smart App before resetting. Any such data is permanently lost.