Influenza was circulating in the region, along with Covid-19 and other viral respiratory illnesses, which were also affecting staff.
Emergency department clinical director Dr Mark Gilbert said people who did not need urgent care should seek treatment elsewhere or manage minor ailments at home.
"Over the weekend, we saw more than 700 people present at ED which led to long wait times for those with less serious illnesses and today is expected to remain busy into the evening," he said in a statement.
Dr Gilbert said people could visit urgent care centres, contact their GP or call Healthline for advice instead.
"This will enable our ED staff to focus on those who really need emergency care and continue to provide quality care, particularly over weekends," he said.
"I would like to emphasise though, that if you are really unwell, we want to see you at ED."
Canterbury DHB spokeswoman Becky Hickmott said people who were not seriously ill could expect long emergency department wait times.
"People with non-emergency conditions are likely to experience a long wait to be seen in ED and at urgent care centres as we need to triage everyone presenting to ensure those in the greatest need, with life-threatening conditions are seen first," she said.
A Canterbury DHB social media post read: "We triage everyone presenting to ensure those in the greatest need, with life-threatening conditions are seen first.
"If you come to ED with something that could be treated by a GP or with advice from a pharmacist, you may be advised of alternative options.
"If after hours care is needed you are encouraged to phone Healthline on 0800 611 116 for free health advice 24/7 or visit one of the Urgent Care centres in Canterbury. Remember, if it’s an emergency – dial 111."
-RNZ & Star News
