Hospitals across NSW and specifically in Sydney's west are under extreme with an influx of patients.

NSW emergency departments are overwhelmed by an influx of patients with doctors saying there's not enough hospital beds.

The latest Hospital Quarterly report from the Bureau of Health Information shows a 25 per cent increase in patients going to emergency departments in the past five years.

Compared with last year, BHI chief executive Dr Jean-Frederic Levesque said there were on average about 900 more patients visiting emergency departments and about 400 more admissions to NSW public hospitals every week.

NSW Health Minister Jillian Skinner told a budget estimates hearing at state parliament on Tuesday the health system was under "extreme pressure" and predicted the current situation would worsen over the next few weeks.

The report findings showed almost half the patients in western Sydney hospitals were waiting longer than four hours for treatment.

"Compared to the same quarter last year, 11,926 extra patients visited our emergency departments, 3,458 extra patients were admitted from the emergency department and 250 more elective surgeries were performed," Mrs Skinner said in a statement on Wednesday, following the release of the report.

But she said while there's been a dramatic increase in demand, NSW hospitals continue to perform extremely well.

"The proportion of patients who received elective surgery in the recommended timeframe is now 97 per cent," she said.

She said the raft of health reforms the government has implemented over the past five years has lead to improvements in hospital performance.

Shadow Minister for Health Walt Secord said the health and hospital system is completely overstretched.

"The Baird government is failing patients - particularly those in western Sydney hospitals," he said in a statement on Wednesday.

NSW Emergency Department faces patient pressure:
* Statewide, 27 per cent of patients waited more than four hours for treatment.
* 19 per cent waited between four and eight hours for treatment.
* 628,525 patients visited the state's emergency departments.
* The median wait for non-urgent surgery in NSW increased by 7 days to 233 days.
* 15 per cent of ambulances were stuck in "bed block" waiting to dispatch patients.