What phrase describes the modern idea of Pandora’s box releasing a chain of troubles?

“Opening Pandora’s box” describes starting a chain of troubles that is difficult to reverse.

The expression comes from the modern retelling of the Greek myth in which Pandora opens a sealed container and releases destructive forces into the world. In everyday English, the phrase is usually metaphorical. It warns that an action, investigation, or disclosure may create many unexpected problems once it begins.

The expression does not normally refer to a literal container. It can describe political decisions, technological experiments, family disputes, or discoveries whose consequences spread beyond the original intention. The phrase is especially useful when one event unleashes several connected difficulties rather than one isolated problem.

The common wording is based on the “box” version, although Hesiod’s original Greek vessel was a pithos, or large jar. That translation history explains why the idiom uses “box” even when discussions of the ancient text use “jar.” The figurative meaning remains stable: opening the container begins an irreversible release of trouble.