The four characters combine to create a powerful image: “worried eyebrows” (愁眉) and a “bitter face” (苦脸). It's a direct and literal description of a distressed facial expression.
In Chinese culture, where emotional restraint and maintaining social harmony are often valued, showing an overtly distressed face can be a significant signal. A `愁眉苦脸` expression is a strong, often involuntary, sign that something is seriously wrong, breaking through the typical facade of calm. Compared to the English phrase “to wear one's heart on one's sleeve,” `愁眉苦脸` is more specific. The English phrase can refer to showing any strong emotion (love, joy, anger), whereas `愁眉苦脸` is exclusively for negative feelings like worry, sadness, and misery. It's closer to “pulling a long face,” but often implies a deeper, more internalised worry rather than just sullenness or a temporary bad mood. Seeing a friend or family member with this expression would typically prompt a question like, “What's wrong?” (怎么了?), as it's a clear, non-verbal cue that the person is suffering and may need support.
`愁眉苦脸` is an extremely common idiom used across all registers of Mandarin, from casual conversation to literature and news.