is killing

(a body part) is killing (one)

A particular body part is causing one pain. Ugh, my head is killing me—do you have any Advil? Phil's back is killing him, so he went back to the hotel to lie down.
See also: body, killing
Farlex Dictionary of Idioms.

something is killing someone

Fig. something is causing someone pain. Wow, my feet are killing me!
See also: killing
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • (a body part) is killing (one)
  • come back and see us
  • be/go back to square one
  • back
  • back at (something or some place)
  • back to square one
  • a while back
  • back door
  • be back on the rails
  • crawl back to (one)
References in classic literature
The Law of the Jungle, which never orders anything without a reason, forbids every beast to eat Man except when he is killing to show his children how to kill, and then he must hunt outside the hunting grounds of his pack or tribe.
Jungle Book
"Let's suppose that these allegations are correct and this is a president who is killing his own people and committed crimes, and the 'free world' and the West is helping the Syrian people against the bad guy," Assad said, as cited by the New Yorker, adding that if this was the case, he would have lost all public support a long time ago.
Assad to US Media: 'Captain of Ship Not to Jump into Water'
She said killing is killing no matter what, stressing that if Duterte has admitted that he is responsible for those killings, then he must be held criminally liable.
De Lima: Duterte must be held criminally liable for ties with Davao Death Squad
"I'll drink to that!" the voice that is killing me laughs, cryptically.
Reflections in church ceilings (excerpt from the unpublished novel: A Casualty of the Peace)