This is a bit of NZIS blurb about what is considered an acceptable standard of health with regard to applications for PR.

[b:66faf3a7d3][color=indigo:66faf3a7d3]Health requirements for residence in New Zealand[/color:66faf3a7d3][/b:66faf3a7d3]

[color=indigo:66faf3a7d3]To be able to gain residence in New Zealand we need to be assured that you and any family members with you have an acceptable standard of health. We impose this requirement to protect public health in New Zealand and to ensure that people entering New Zealand do not impose excessive costs and demands on our health and special education services. We also want to make sure, where applicable, that people who enter New Zealand are able to undertake the functions for which they have been granted entry.

Generally, we will not approve people for residence in New Zealand if they:
? require dialysis treatment
? have active pulmonary tuberculosis (TB)
? have severe haemophilia
? have a physical incapacity that requires full time care.

Note: Skilled Migrants who submit an Expression of Interest will not go into the Pool if they have one of the conditions listed above.

We will consider that people have an unacceptable standard of health for residence in New Zealand and may decline their application for residence on this basis if they:
? are likely to impose significant costs or demands on New Zealand?s health services or special education services
? are not able to undertake the work on the basis of which you are applying for a visa or permit, or which is a requirement for the issue or grant of the visa or permit (unless you are sponsored for residence by a person who holds refugee status in New Zealand).

Note: The conditions listed at Appendix 10 of the Immigration New Zealand Operational Manual are considered to impose significant costs or demands on New Zealand?s health services or special education services.[/color:66faf3a7d3]

There's some more stuff here and here which might throw some light on what sort of thing they're looking for. I don't know how far ahead they'd want to take the matter with regard to risks that might arise in the future.