A security guard who was badly beaten with an oxygen cylinder while on duty at Waikato Hospital will be off work for at least three months.

"She's got no independence at the moment. She can't do anything ... She struggles to even make a coffee," her son Carl Harney told the Herald.

His 47-year-old mother, who doesn't want to be named, and three nurses were attacked by a male patient in the early hours of May 14.

Today, her family are speaking for the first time, saying she wasn't warned that the incident she was called to had the potential to be dangerous - and it's not the first time guards have felt unsafe in their job.

Harney said guards were called to an attempted self-harm incident, but not that they were entering a potentially dangerous situation.

"Mum was told there was a (person threatening to self-harm) going up the stairwell in the Menzies Building. And it wasn't that - it was something violent."

The male patient had broken into the ward and assaulted three nurses before grabbing an oxygen cylinder and attacking his mother. Harney believes he had already injured a nurse on his ward below.

"He saw mum standing there with a big yellow jacket on and mum was just stuck in a corner."

She tried to grab a chair in self defence, but they were all long benches.

His mother's memory was pretty hazy after that.

She suffered a broken wrist and torn ligaments in her other arm, and required surgery for multiple facial fractures after the assault. The nurses were treated in the emergency department before being discharged.

The guard's daughter Tajuana Eltringham said it was extremely upsetting seeing their mother battered and bruised, and she struggled with what to tell her younger siblings, aged 7 and 9.

"I burst into tears and walked out, it was a massive shock seeing my mum like that."

The guard's family are speaking out on their mother's behalf because they say she can't because she and other security guards have been muzzled by their employer, Allied Security.

Harney said it was not the first time guards felt unsafe while at work and called on Allied and Waikato DHB to have better safety measures in place. He believed better communication may have also prevented the incident.

"There are a lot of the guards, not just my mum, who say they're not safe. That guy shouldn't have been on that ward."

Her mother had worked at Waikato Hospital for two years and loved her job and the people she worked with.

The family's criticism lay with the upper management of Allied Security and Waikato DHB, and said staff were overworked and underpaid.

Allied Security had also not offered any counselling for any of the workers, Harney said.

Waikato DHB and Allied Security took the guard's family meals in the first week - but the family says there has been no support after that.

E tū senior organiser Iriaka Rauhihi said Allied Security's media ban meant guards could not speak out about important health and safety issues because they risked losing their jobs.

"They should have the right to voice their legitimate concerns about this, but they don't."

Waikato DHB and Allied Security have been approached for comment.