I understand you use the Share icon in the Health app, and select Mail, which opens the Mail app with that PDF included as an attachment. Attempting to send that email doesn't work. Is that correct?
Can you explain exactly what fails, or in what manner? The reason for asking is that it's just like any other email message with a file attachment. Fixing that particular problem is almost certainly related to some kind of limitation related to the email service provide you're using, so I'd look into that first.
Anyway, since you asked about other options. The Share icon also allows you to use AirDrop, or save it to Files, or send it via the Messages app, print it directly to an AirPrint-enabled printer... those sorts of things.
If you don't mind I'm going to ask the site Hosts to relocate your question to the iPhone Community because I think that's where it needs to go. After taking an EKG, the PDF winds up on your iPhone.