Flare and crash days
From the app’s English Help & Guide · Reference release 1.0.13
A flare day means symptoms have worsened significantly. A crash day means they've hit an energy wall, often from doing too much previously.
When a flare or crash is active, Supported shows a condition-specific guide at the top of their detail page — what to do, what to avoid, what to say, and when to seek help.
You can enable notifications for flare and crash days in More > Notifications.