To protect a health account, turn on two-factor authentication. The term means that two proofs are needed to get in: your password, then a code sent to your phone.
In the app, open Profile or Security.
Turn on Two-factor authentication (or « two-step verification »).
Follow the steps: the app sends a first code by text or by email. You should see an « Enabled » message.
If the app offers backup codes, write them down somewhere safe.
If you don’t see it: the option does not exist in every app. A long password, used nowhere else, is then your best protection.
Limitation: without your phone, you no longer receive the code. Backup codes, when the app offers them, are what serve you then; otherwise only the app’s help service can restore access.
To picture it: it is a door with two locks.
Good to know: never give this code to anyone, even to someone who says they are calling from the clinic.