Definition: A fundamental pathologic process consisting of a dynamic complex of histologically apparent cytologic changes, cellular infiltration, and mediator release that occurs in the affected blood vessels and adjacent tissues in response to an injury or abnormal stimulation caused by a physical, chemical, or biologic agent, including the local reactions and resulting morphologic changes; the destruction or removal of the injurious material; and the responses that lead to repair and healing. The so-called cardinal signs of inflammation are rubor, redness; calor, heat (or warmth); tumor, swelling; and dolor, pain; a fifth sign, functio laesa, inhibited or lost function, is sometimes added. All these signs may be observed in certain instances, but none is necessarily always present.
[L. inflammo, pp. -atus, fr. in, in, + flamma, flame]