Allostasis
Allostasis is the process of achieving stability, or homeostasis, through physiological or behavioral change. This can be carried out by means of alteration in HPA axis hormones, the autonomic nervous system, cytokines, or a number of other systems, and is generally adaptive in the short term (McEwen & Wingfield 2003). Allostasis is essential in order to maintain internal viability amid changing conditions (Sterling & Eyer 1988; McEwen 1998a; McEwen 1998b; Schulkin 2003).