The modern English expression for a source of unforeseen troubles is “Pandora's box.” It comes from the later tradition that transformed Hesiod's large jar into a box and made the container the central symbol of dangerous consequences.
In ordinary English, opening a Pandora's box means starting a process that releases many unexpected problems and is difficult to reverse. The phrase is used in journalism, politics, science, law, and everyday conversation, often without any claim that the speaker is recounting the whole Greek myth.
The expression rests on a translation history. Hesiod's Greek text uses pithos, a jar, while Erasmus's Latin rendering used pyxis, a box or container. That later wording became influential in European languages and eventually produced the standard English phrase.
The phrase is sometimes used as though Pandora deliberately wanted to cause harm. In Hesiod's story, however, Zeus's divine plan and Pandora's role are more complicated than the modern idiom suggests. The idiom preserves the image of consequences escaping into the world.