The modern expression “Pandora’s box” describes a source of many unexpected troubles, based on Pandora’s Greek myth. In ordinary English, opening a Pandora’s box means beginning an action that releases a difficult or damaging chain of consequences.
The expression comes from the story in which Pandora opens a container and the world’s illnesses and hardships escape. Although the earliest Greek account describes a jar, the word “box” became standard through later translation and retelling.
The phrase is now used far beyond mythology, including journalism, politics, science, and technology. It can describe a decision, discovery, or policy whose consequences are difficult to control. The expression does not usually refer to one specific danger; it means a broad release of unforeseen problems.