Inflammation is commonly associated with many prevalent disorders, and uncontrolled inflammation is considered one of the key players in many chronic and age-related diseases of Western society. Despite this association, not all inflammatory responses are necessarily harmful; rather, inflammation plays an essential physiological role in responding to stress, dysfunctional tissue states and injury. Inflammation that is caused by stressed, apoptotic cells or metabolic changes acts as an extension of the autoregulatory capacity of the organism and helps to maintain and/or restore a healthy functional tissue state. An array of molecules regulates inflammatory responses. Molecules act to limit the severity and duration of the inflammatory response and allow for resolution to occur (the ideal outcome of acute inflammation). Pathology occurs when the inflammation cannot be resolved; it therefore becomes chronic and is maintained by positive feedback loops.
The importance of inflammation physiology in responding to stressors and restoring autoregulation reveals that the regulated inflammatory process itself is not harmful; rather, the inadequate response to either excessive or insufficient inflammation leads to pathology. Inflammation resolution is an active process triggered at tissue level, in which endogenous anti-inflammatory and pro-resolving mediators actively counter-regulate the onset of inflammation in order to promote resolution. Whereas the pathological consequences of non-resolving inflammation include tissue injury, scarring and fibrosis, acute inflammation is necessary to return from a disease state to health.