Inflammation is the immune system’s response to injury and infection, and quick decisions must be made when one or both are present. If the immune system detects an infection, it also looks for signs of injury (broken cell parts, spilled cell constituents). The reverse holds as well — after sensing an injury, the immune system searches for telltale signs of the presence of microbes launching an infection. In many cases, both an infection and an injury set off an inflammatory response. After massive tissue damage caused by trauma and/or burns, a systemic inflammatory reaction can set in.