British Expats - Medical

It is probably easier to state what the medical doesn't consist of !
It is a complete and thorough physical check up and the doctor doing it will report their findings as they go along. They may discuss health stuff with you in the appointment but they don't make any determinations for Immigration purposes. Their job isn't to make any decisions on the state of your health, only give answers to the Immigration medical requirements and will complete the report in real time using a pen that records everything that it written so it is impossible it can be altered. It's all reported digitally nowadays using e-Medical whereas when we did them, we had to collect all the documents, test results and x-rays, hand back to the doctor who would seal it up in an envelope and we then took it away and sent it off to Immigration. All that jazz has been cut out of the process now. It is all sent electronically in real time.
If there are any issues with your medical, any levels that are borderline or outside of their threshold, Immigration will hand it to a Medical Assessor to determine prognosis and likely costs to the NZ health system. It is the MA that decides whether or not you have an adequate standard of health. Immigration cannot legally decline a visa on health grounds without the backing of an approved medical assessor.

It is nothing to worry about. It is just a medical.
Nothing you can do but chill out and do what the doc asks you to do.