An ageing population, workforce pressures and increasing costs have been identified as major challenges facing the NSW health system.

But despite pressures, the state's public health system has demonstrated its resilience and performance compared to interstate and international counterparts, an inquiry has been told.

The Special Commission of Inquiry into Healthcare is seeking to identify areas of cost and wastage within NSW Health in order to make better use of staff and funding.

In the first hearing, counsel assisting the commission Ed Muston SC outlined the key themes identified so far in submissions to the inquiry.

Mr Muston said the upcoming inquiry would be policy-based, not adversarial.

"No one should feel apprehensive about this inquiry (and) no part of it involves searching for errors made by any particular person or group of people working within the wider health system in NSW," he said on Monday.

"The purpose of the inquiry is to identify key challenges faced by the health system now and into the future, and to search for the best ways for the system to adapt to meet those challenges."

Mr Muston identified several recurring issues raised in inquiry submissions, but the state's ageing population was one overarching theme.

The changing demographic of NSW's population meant people were living longer meaning there is a shift towards age-related chronic conditions needing treatment.

Richard Cheney, representing NSW Health, said the inquiry would help future-proof the state's public health system.

"The burden of disease has changed significantly over the last 20 years with an increased prevalence of conditions associated with and mental health issues and escalating numbers of those with chronic diseases," he said.

"NSW Health sees this inquiry is an opportunity to drive further reform to ensure a health system that's fit for the future and can meet the needs of NSW communities."

Workforce pressures as a result of low pay rates compared to other states and overseas and spiralling treatment costs are expected to be another key theme in upcoming hearings.

Mr Muston said the inquiry would also examine where the system was performing well and what processes could be duplicated across NSW to improve services.

"When the system is working great we don't hear about it, but as a result of that the impression that one is left with is slightly one-sided," he said.

"Where the system is working well will provide fertile ground for identifying ways in which things might be changed and improved in areas where it's not."

Australia spends more than $240 billion on health care each year, including $51 billion from individuals and their health funds.

Three-quarters of every dollar goes to hospitals and primary health care, according to the Australian Institute of Health and Welfare.

The NSW government alone will spend $34.3 billion this financial year or $93 million a day.

The special commission, which will have royal commission-style powers, has been described by the state health minister as a "once-in-a-generation" look at the troubled system.

Barrister Richard Beasley is leading the inquiry after previously serving as senior counsel for a probe into the Ruby Princess COVID-19 outbreak and as commissioner for two local government inquiries.

His final report is due in August.