The Labour Department is investigating an alleged assault on an Otago District Health Board nurse last month which has been classified as a serious harm notification.
Board chief nursing officer Teresa Bradfield said she could not give details of the incident other than to say it involved a female nurse and an unwell patient.
The nurse was off work recovering.
Such incidents were always of concern and when they occurred staff always looked at the circumstances surrounding them to see if there was anything that could be done to avoid a repetition in the future.
"Nurses do face aggressive, violent situations sometimes, and it can be very stressful."
The nurse was being supported and it was expected she would eventually return to work.
Ms Bradfield said such serious incidents involving assault were not common, although this was the second one in six months.
Less serious assaults did occur.
Reports to the board's hospital advisory committee show that this year between two and eight assaults have been recorded each month.
