As with most things, there are agreed ways of working for reporting and dealing with confrontations. Depending on the workplace, there might be a policy for responding to challenging behaviour that you have to follow. You should take the time to familiarise yourself with it so you know what to do if you are faced with challenging behaviour.
There will also usually be a form that you have to fill out to report on what happened. You should explain what happened, who was involved, and where and when the incident took place. As well as that, you should include whether anyone was injured or whether the police were called, and sign and date the form before handing it in. This will be used to determine how to support the individual better.
You should complete a form if there is one, or at least notify your manager whenever there’s a confrontation. It is important that the confrontation is made known, as future confrontations may be worse if nothing is done about it. It is your duty to make sure that any conflict is reported to the right people in the correct way.