What is the origin of the idiom "up in arms about something" and when to use it?

The phrase "up in arms about something" has its origins in medieval times and dates back to the 14th century. It was initially used in a literal sense to describe the act of being armed with weapons in preparation for battle or conflict. Over time, the phrase evolved to also carry a figurative meaning, referring to a state of anger, outrage, or protest. It is commonly employed in discussions related to politics, social matters, or public controversies that evoke passionate emotions.