When a wound swells up, turns red and hurts, it may be a sign of inflammation. Very generally speaking, inflammation is the body’s immune system’s response to an irritant. The irritant might be a germ, but it could also be a foreign object, such as a splinter in your finger.This means that an inflammation doesn’t only start when, for instance, a wound has already been infected by bacteria, is oozing pus or healing poorly. It already starts when the body is trying to fight against the harmful irritant.Causes of an inflammationMany different things can cause inflammations. These are the most common:Pathogens (germs) like bacteria, viruses or fungiExternal injuries like scrapes or damage through foreign objects (for example a thorn in your finger)Effects of chemicals or radiationDiseases or medical conditions that cause inflammation often have a name ending in “-itis.” For example:Cystitis: an inflammation of the bladderBronchitis: an inflammation of the bronchiOtitis media: an inflammati...