My Health Record is a government managed service through which you may access your health information from anywhere within Australia.
Registered Healthcare providers may also access this information; a record is maintained of who and when information has been accessed.
I find it increasingly useful to checking immunisation history (although apart from immunisations given to children born in the 1990’s or later, the longer ago a vaccination was given the less likely it might appear) and pathology results (mainly from 2021 onwards).

The information available includes pathology (blood tests) and radiology (xray, ultrasound, CT scan and MRI) results, immunisation details (including covid and influenza vaccines), hospital discharge summaries and whatever other information has been uploaded by private GPs and specialists you have attended (usually this is of a ‘Health Summary’ nature).

What is available basically depends on what has been uploaded; in my experience pathology and radiology results from private providers such as Dorevitch or I-Med radiology are uploaded to MyHealthRecord unless advice to the contrary is given at the time by the patient.
By mutual agreement, you can request for any information in your file to be added to your MyHealth Record, and patients may upload personal health, allergy and medication information after signing in via MyGov.
If requesting an upload, my advice is to book a separate consultation, as like anything of this nature, it can be more complex than thought.

Finding the answers to questions that patient may have can be somewhat confusing, as you are referred to additional Government websites besides the MyHealthRecord website ie
DigitalHealth https://www.digitalhealth.gov.au/initiatives-and-programs/my-health-record/
MyGov https://my.gov.au/
Medicare Online https://www.servicesaustralia.gov.au/medicare-online-account
Its often easier to ring the number listed, if problems are encountered.

If wishing to restrict access between the various government portals, I noted that a Medicare Online account or linking to MyGov is not essential (but a Medicare number and other information such as details about Medicare claiming history are needed).

This seemed to be a good ‘howto’ link at the time of writing the article:
https://www.digitalhealth.gov.au/support/frequently-asked-questions