The problem this product is built around
A single HRV number is easy to overread. Sleep, exercise, illness and measurement conditions can move it, so a population threshold may turn normal variation into alarm.
How Cozy solves it
Cozy reads SDNN in read-only mode and compares it with a personal baseline on device. Weekly and monthly views place the trend beside moods and factors without turning it into diagnosis. Open the Cozy product page for current availability and plan details.
A practical workflow
- Log mood for several days first.
- Grant read-only Apple Health access.
- Compare changes with sleep and illness.
- Discuss persistent concerning patterns with a professional.
What to check before you trust the result
SDNN has many causes and missing data can make a trend incomplete. A personal baseline is context, not a clinical threshold.
Who this workflow is for
Use it when you track mood and want gentle pattern awareness.
Go deeper
For detailed mechanics, read See the HRV model and Keep input small.
Cozy is useful when it shortens a repeated decision while keeping evidence, assumptions and stopping points visible. Start with one real task, inspect the result, and then make it part of your routine. Try Cozy.