Staff at Auckland Hospital have made hundreds of reports about fleas and other insects, and one patient there slipped and fell trying to stomp on a cluster of cockroaches in the shower.

The patient, Claudia Elliot, was staying in the hospital's cardiology ward last month after having open heart surgery.

She praised the clinical care she received but told RNZ she had serious concerns about the hospital's condition and resourcing.

"I have spent 10 years working for the UN in the hot spots of Afghanistan and Somalia," she said. "So I'm sort of used to a bit of Third World colour. But I was very surprised when I went in for a shower in the cardiology recovery ward to see that there were a number of small cockroaches in the shower."

Elliott said she tried to stomp on the three small bugs, but slipped and fell.

"I yelled out, and there were about 10 staff members who came racing, picked me up and took me down for an MRI scan to make sure I hadn't done any damage to my head when I fell."

She hadn't - but the cockroaches were not the only concerning observation.

"When I had a heart monitor on, the heart monitor didn't work, so they had to change it for another one. The second thing that didn't work was the drip, and they had to change that for another one."

Staff were also in short supply, she said, with one staff member for five post-surgical patients on her ward. A physiotherapist told her there were two of them on shift, with a case load of 36 patients that day.

A Nurses Organisation delegate told RNZ there had been a recent increase in reports of fleas, cockroaches and other insects within the wards.

Many wards still had carpet flooring, which was the perfect breeding ground for fleas, they said.

The Health NZ website says cockroaches can spread diseases like dysentery, salmonella and diarrhoea, and they "thrive in unhealthy environments".

The delegate understood some wards were going to be refloored with vinyl in the coming months, although the work had been delayed by budget restrictions.

"In my wards that I work in, we've got two toilets that don't have the toilet seat lid," the delegate said.

"It's quite common for bathrooms to not have hot water running. It's quite common for showers to have very low water pressure.

"So patients have to then go and find another room to have a shower in, which causes more struggle in terms of logistics."

They said it was also common for observation equipment to malfunction, or not collect accurate data.

"So we send the equipment off for maintenance checks and to get repaired or get new ones.

"But because there's quite a strict, tight budget within the hospital at the moment, nurses are having to stretch two or three throughout the whole ward."

Patients and staff had reported flea bites, with some staff even reporting accidentally passing them on to their own homes and families.

"Our patients shouldn't have to have to deal with this in the hospital," the delegate said.

"And it's quite embarrassing as a healthcare worker in the hospital knowing that our standards should be really high, but we're not given the resources or the safe environment to be able to provide our care."

Health NZ's group director of operations for Auckland, Dr Michael Shepherd, told RNZ in a statement: "Like many large campuses, we have experienced flea activity from time to time."

He said 142 flea-related incidents had been reported across Health NZ's Auckland sites in the past year.

"These reports are actively managed through our pest management programme and have reduced significantly in recent years," he said.

Shepherd said there were comprehensive cleaning, facilities and equipment maintenance programmes operating 24 hours a day, seven days a week.

Work to replace carpeted areas with vinyl flooring was underway across Health NZ facilities, but had to be carefully planned to minimise disruption as it often required clinical services to be temporarily relocated, he said.