Extreme pressure on the health system as emergency departments are being overwhelmed by people who can't afford to visit GPs.

Counties Manukau Health is pleading for people with non-urgent complaints to keep emergency departments free for people most in need.

PSA national secretary Erin Polaczuk said the system is being pushed to breaking point.

"They talk about working really long hours, they talk about working a lot of overtime and double shifts to the point where they're exhausted."

Middlemore Hospital said it's providing extra staff and added additional beds to cope with record demand.

Hawke's Bay Hospital is at capacity and is also urging people to stay away from its emergency department unless it's urgent.

Chief Medical Officer John Gommans said winter has added more flu-like illnesses to an already busy time.

Now, some minor surgeries have been postponed until further notice.

Dr Gommans said people starting to feel unwell from winter viral illnesses should get early advice from their doctor or pharmacist, or call Healthline.

"Please remember that the emergency department is the place to go for life threatening, urgent treatment," he said.

"People with minor injuries or illness, such as colds, can expect to wait for long periods to be seen, as patients needing urgent care are always prioritised."

Additional reporting by NZ Newswire