Nurses and paramedics could face job cuts of up to 10 per cent as NSW Health contemplates ways to deal with an anticipated financial shortfall of $7 to $10 billion over the next decade.

A leaked internal presentation - parts of which were obtained by The Sun-Herald - shows senior bureaucrats are considering several means of "dramatic change required to close the gap" and reduce the department's spending by 20 per cent in the next 10 years.

A slide from a recent NSW Department of Health presentation detailing an estimated shortfall of $7 to $10 billion over the next decade.

The slides were shown at a high-level strategy and planning meeting in November, and cited rising demand, changing demographics and patient needs, and growing complexity as the three key reasons for future budget overruns.

NSW Health estimates it will need to slash a fifth of its overall spending to avoid a funding shortfall of $7 billion to $10 billion, including a 10 per cent reduction of its workforce, 20 per cent fewer emergency presentations and 20 per cent fewer outpatient visits.