Although the hospital plans for higher capacity levels at this time of year, adult demand has substantially increased over the past month.
"All of our forecasting didn't anticipate the demand that we've had this winter," Wilsher said.
"We don't really understand the reasons for that demand because the influenza season hasn't peaked yet."
"We're hoping we don't see a big peak this year. But it's too early to tell."
One of the factors driving demand was growth in the number of older people who were arriving at ED with multiple conditions.
Another factor has been patients with minor illnesses who could have seen their GP or an accident and medical clinic instead of going to the emergency department.
Wilsher said that waiting times were not getting worse and all patients were being treated safely. But she said that people with mild conditions like a sprained wrist or a cold were likely to be facing a long wait for treatment - possibly longer than the target time of six hours.
A new 24-bed unit was opened at the hospital in May and was designed to lower the number of people in ED and reduce unnecessary admissions. More beds have been added to the general wards to cope with Auckland's growing metropolitan population. The hospital is also planning a new stroke unit, which will free up some of its beds.
Counties Manukau Health is also currently experiencing very high demand for ED services, with the number of patients attending Middlemore Hospital in the past week reaching 2477.
This compares with 2338 at the same time last year.
Both hospitals strongly advised people to protect themselves and their whānau by visiting their GP early and to contact Healthline for free information.
"Many of the patients we see could have avoided hospitalisation if they had seen their GP when they first experienced symptoms," Wilsher said.
"We are particularly concerned for the very young and the very old in our community."
A national target for ED waiting times was dropped last year by the new Labour-led Government.
At last count just under 90 per cent of patients within the ADHB were being seen within six hours. The target was 95 per cent.
You can help look after yourself and your whānau by:
• Ensuring you and your whānau have this season's flu vaccination.
• Visiting your pharmacy for minor health conditions and queries.
• Seeing your GP for all non-urgent health concerns.
• Visiting your local accident and medical clinic for minor illnesses and injuries.
If you're unsure where you should go, call Healthline for FREE advice from a nurse on 0800 611 116 or visit Healthpoint.
If it's a serious or life-threatening emergency, don't hesitate to go to the emergency department or call 111.
