Inflammatory molecules (cytokines) signal to the body that there is an issue in a particular area.

“inflammatory molecules that are signaling to the rest of the body hey there's something going on here there's either some intrusive object and indeed if you were to get you know a bb or a splinter into a particular uh you know skin area there'd be a lot of inflammation so it could be the introduction of a foreign physical object into an area that will cause inflammation it can be the presence of some sort of local toxin in that area it could be a more systemic inflammation”