What modern expression describes releasing a problem that cannot easily be contained, like Pandora’s container?

“Opening Pandora’s box” describes releasing problems that are difficult to contain or reverse.

The expression comes from the myth in which Pandora opens the container given to her, allowing evils and hardships to spread throughout the world. In modern English, the phrase is used figuratively for an action that creates many unexpected complications. It usually suggests that the consequences cannot simply be put back as they were.

The idiom is related to, but not identical with, “opening a can of worms.” Both expressions describe troublesome consequences, yet “Pandora’s box” specifically refers to a single act that unleashes multiple problems from a concealed source.

The popular wording reflects a translation history: Hesiod’s original object was a jar, while later Latin and European usage made it a box. The expression is now familiar far beyond classical studies and is used in journalism, politics, law, science, and everyday conversation.