I too am interested in an automated system taking data from things like smart rings/watches, ideally with home assistant integration. Do you mean like basic note taking? something like Joplin could be used for that. I use it extensively. It has a to do checkbox function, which you could use as a reminder, though it doesn't pop up. You'd have to look at it. I think for reminders etc. you'd perhaps be looking at calendar software, perhaps next cloud, which also includes notes.

Components of GNU Health, perhaps?

There's this, even

Nextcloud Health?

Edit: Appears not not do the job after a dig. Maybe Gadgetbridge (if you're pulling in fitness trackers)>Influx?

I have no experience with it, but this promises local storage of health records: https://github.com/fastenhealth/fasten-onprem

I am there right now, tried every open source project about health records, they all either suck or just not appropriate for personal use (ie meant for hospital use)

Recently a new project came out and it is the only one that is actually usable, and will possibly get really good.

You should try all the options for your self:

• OpenMRS
• Fasten
• OpenEMR
• The only good one IMO: MediKeep

Paper notebook for each person, really the simplest, unless you have continuous monitoring or something uploading data automatically. Otherwise, for stuff like weight and BP, the actual measurements are the main hassle and computers won't save you any time compared to that.

Added: for pills, timercap.com bottle caps are brilliant. They have an LCD display saying how it has been since the cap was last taken off the bottle. It eliminates the problem of forgetting whether you have already taken your pill.

Otherwise, generally, as always: https://biggaybunny.tumblr.com/post/166787080920/tech-enthusiasts-everything-in-my-house-is-wired

A friend of mine is building something like that. You scan all the documents and you can set reminders, it does summaries and proposes actions and a buck of other really neat stuff It's ai. I think it's a good use case. But the ai means it has to call a server with the information, so I can't get past that.

You could build your own spreadsheet using LibreOffice Spreadsheets.

I've been meaning to do it because my diet doesn't change much, and it would just be easier to track it myself.