The Whanganui District Health Board website says visiting hours are 2pm to 8pm daily, but can be flexible for the Emergency Department, Children's Ward, Critical Care Unit or Acute Assessment Unit.
The woman said staff had "no control over visitors". It was common to have 10 to 20 family members visiting one patient and many of them became "volatile" towards staff.
"Recently, we've had nurses being intimidated because of race," she said, referring to a family making racial slurs against nurses of Indian, Fijian and Asian descent.
She said staff had been hit, had things thrown at them, and been grabbed roughly, leaving bruises.
"Some night staff had to lock themselves in the smoko room. There's a big hole in one of the doors where a patient attacked the door.
"A lot of them come in and they're already hyped up on God knows what."
She said some patients discharged themselves because they felt unsafe in the wards, and she had received serious threats and often felt unsafe.
People had raised their fists at her, pointed fingers in her face and stood close to intimidate her.
The woman said there was no use complaining. There was a report to fill out if staff had complaints, but she had never seen anything come from it.
More regulation on visiting hours would help with the safety, as well as more staff.
"We're so understaffed, it's unbelievable," she said. "Nurses can have up to seven patients [and] you're dealing with six volatile families."
Nurses did what they could to provide good service but had to be mindful there was "no support from management".