what's eating you

What's eating (someone)?

What's bothering someone? Why is someone in a bad mood? What's eating Terry today? I asked him how his weekend was and he just glared at me. I've never seen her act that way before. What's eating her?
See also: eating
Farlex Dictionary of Idioms.

what's eating you

Also, what's bugging you. What is annoying or bothering you? For example, We've conceded just about every point, so what's eating you now? or You're in a terrible mood-what's bugging you? The first slangy term, dating from the late 1800s, presumably uses eat in the sense of "consume"; the colloquial variant, from about 1940, uses bug in the sense of "annoy." Also see what's with.
See also: eating
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • a stranger to (someone or something)
  • be in bad with (someone)
  • accompany (one) on a/(one's) journey
  • accompany on a journey
  • be out of (one's) league
  • be out of somebody's league
  • (one) puts (one's) pants on one leg at a time
  • bargain
  • bargain for (someone or something) with (someone)
  • brief (someone) about (someone or something)
References in periodicals archive
The first exercise in What's Eating You? is a three-page questionnaire to help teen looks at their eating behaviors.
An Instant Help Book for Teens
What's eating you? Corrosion is insidious and ever present.
Hank Caruso's Aerocatures[TM] sketchbook: Navy's aging aircraft
What's eating you is that he's stopped being a mug and your crocodile tears have no impact.
Dr Miriam: HE CAN'T FORGIVE