Health App using 23% of battery in last 10 days

The last couple of days my iPhone X’s battery percentage is much lower than usual at the end of the day. The number one culprit is Apple’s own Health App, which apparently used 23% of the battery in the last 10 days (with only 11 minutes of screen time in those 10 days).

How can I diagnose/fix this?

Try shutting off the phone for a minute and restarting in order to quit wayward processes.

That helped for a little while, but in the last 24 hours it was again 19%.

Hopefully the update to iOS 12.3 improves this (as a side effect).

This only got worse over time…

Lately it’s between 30% and 40%; every single day (with only a few minutes of screen time per day).

Initially I blamed the COVID-19 exposure feature, but that’s now listed separately and using less than 5% per day.

Any idea what might be going on and how to fix this?