open a can of worms

idiom/ˈəʊpən ə kæn əv wɜːrmz/ 🔊 listen

Open a can of worms means to bring up a topic or take an action that creates many new, unexpected, and complicated problems. Like opening a can full of worms, once you start, it's hard to put everything back in order.

📖 Meanings

1to raise an issue that creates many unexpected problems
"Asking about the budget really opened a can of worms." — Asking about the budget created a whole tangle of new problems.
2a seemingly simple matter that leads to bigger trouble
"Let's not open that can of worms." — Let's not get into that — it'll cause a lot of trouble.

🔄 Related phrases

stir up trouble →open Pandora's box →start a whole mess →

💬 Common patterns

open a can of wormsthat opened a can of wormsdon't open that can of worms
❓ How do you say you raised a topic that created many new problems?