牵肠挂肚

qiān cháng guà dù

to worry about someone constantly

Character by character

牵qiān
pull

肠cháng
intestines

挂guà
hang

肚dù
belly

孩子第一次出远门，妈妈牵肠挂肚，一夜没睡好。

The first time her child went far from home, the mother fretted so much that she hardly slept all night.

Tone: neutral.

Mostly of family worrying about someone who is away; warm and colloquial. Close to 放心不下 and 惦记, but stronger.

Learn this in Lesson 226 · HSK 9+: 家书 (Letters home)

A dialogue, a reading, word cards with audio and a drill that uses it, in Learn Chinese with Bao. The first lessons of every level are free.