iOS 15
Manually add data in Health on iPod touch
You can manually enter data like body measurements, symptoms, and menstrual cycle information in the Health app 
.
Tap Browse at the bottom right to display the Health Categories screen, then do one of the following:
Tap a category. (To see all categories, scroll down.)
Tap the search field, then type the name of a category (such as body measurements) or a specific type of data (such as weight).
Do any of the following:
Add information to the Cycle Tracking category: See Track your menstrual cycle in Health on iPod touch.
Add information to the Sleep category: Tap Add Data at the top right.
Add information to other categories: Tap
for the data you want to update, then tap Add Data at the top right.