The common English phrase for unintended trouble released by opening Pandora’s container is “Pandora’s box.” In modern usage, it describes an action or discovery that creates many unexpected problems or consequences.
The expression comes from the Greek myth recorded by Hesiod, but its wording is historically secondary. Hesiod describes a pithos, or large storage jar, rather than a box. The “box” version became dominant through later translation and retelling.
The phrase is now used far beyond mythology. Journalists, scientists, lawyers, and ordinary speakers may call a risky innovation or complicated decision a Pandora’s box when they mean that its consequences may be difficult to control.
It is often confused with “Pandora’s jar,” which is closer to the ancient source, or with unrelated idioms such as “opening a can of worms.” The canonical modern English expression remains “Pandora’s box.”