What is the common English expression for opening Pandora’s box used to describe?

The expression “opening Pandora’s box” describes creating many unforeseen problems.

The idiom comes from the myth in which Pandora opens a container and releases troubles into the world. Because the consequences spread beyond the original action, English speakers use the phrase when a decision or investigation produces a chain of unexpected difficulties.

The expression is usually figurative rather than literal. It can refer to politics, technology, family disputes, legal questions, or any situation in which examining one issue exposes many more. The phrase does not normally mean that the person intended to cause harm.

A related detail is often overlooked: the ancient Greek story used a large jar, or pithos, rather than a box. The box wording became standard through later translation and cultural retelling, while the metaphor retained the original story’s central idea of consequences escaping control.