The Health Metric events are generated based on an internal DSM (eg. doesnt count against the license, does not show up in log sources, etc). However, these events can be enabled/disabled/configured. To disable/enable:
1. Admin tab
2. Custom Event Properties
3. In the filter field, type 'Health'. This will display all the internal log sources of type 'health metric'.
4. Highlight the one(s) you want to disable and click on the 'disable' button.