Dunedin Hospital has been at 108 percent capacity this week, one of several around the country still slammed by high demand.

Emergency nurses said it meant more risk for patients and stress for workers.

RNZ asked every hospital for a snapshot of how full it was at 8am on Wednesday.

Palmerston North (104 percent) and Waikato (101 percent) were also above their maximum capacity, while Christchurch, Hawke's Bay and Waitākere were at 100 percent occupancy. Auckland and North Shore hospitals were at 99 percent.

Most others around the country were well into the 90 percent region.

College of Emergency Nurses chair Sue Stebbeings said if a hospital was at or over capacity, it meant patients were backing up in the emergency department, unable to be moved into a hospital bed because none were available.

That had a big flow on effect.

It meant emergency departments filled up, then people would start to be cared for in corridors or ambulance bays. After that more people would arrive, filling the waiting room then often spilling out in to main hospital corridors.

Nurses were constantly having to move people in and out of places, she said.

"You might sit someone in a chair, talk to them try and provide some pain relief, try and provide whatever they need next - medication, a warm blanket - and then you might ask them to take a seat back in the waiting room so you can bring the next person in to do that," she said.

One of the big stresses for nurses in a full waiting room was welcoming new people, while keeping an eye on who was waiting, and prioritising who should get the next bed.

She worried about people getting sicker or collapsing while they waited.

"We are here for our communities. The reason we are here is that we really want to provide good emergency care. We're speaking up because we're not able to provide that care and we need to find ways forward," Stebbeings said.

Nurses also worried about people leaving early or not coming at all.

If patients were thinking of leaving, Stebbeings wanted them to at least try to talk to a nurse so they could get some individual advice.

There was still no noticeable decline in patient numbers in most hospitals, despite the peak of the Covid-19 and flu season being over for months, she said.

Any fix for the busy EDs was very complex but having enough staff, keeping them well trained and avoiding burnout were critical starting points, she said.

The College of Emergency Nurses is part of the New Zealand Nurses Organisation.