The number of assaults on staff at two Teesside hospitals have doubled over a period of six years, figures show.
The North Tees and Hartlepool Trust said 179 assaults were recorded last year, including 18 reported to the police.
It is compared to 88 assaults on hospital staff in Stockton and Hartlepool in 2010.
Mike Jill, from public services union Unison, said the figures were "alarming".
"Health service staff are there to do a job of work; they're compassionate, they're there to help people," he said.
"The last thing they want is somebody attacking them in the workplace."
The trust said it treated every case seriously and staff were offered conflict resolution training.
It said most assaults were committed by people with mental health problems and dementia.