Homeostasis 3: nurses as external agents of control in hypothyroidism.

The role of healthcare practitioners in reversing homeostatic imbalances essentially makes them external agents of homeostatic control-they are replacing the usual assessment, controlling and effector aspects that operate intrinsically in health (homeostasis) but have failed in ill-health (homeostatic imbalances). This article examines the homeostatic imbalance of hypothyroidism, using a case study to draw analogies between the components of homeostatic theory and those of the nursing process. After reading this article, nurses should be able to explain: how the components of homeostasis are associated with health, and how failure of one or more of these components of homeostasis is associated with illness; that illness arises from a cellular, and therefore chemical, homeostatic imbalance; that hypothyroidism is a cellular imbalance of low levels of thyroid hormone, which is identified by signs and symptoms (i.e. other homeostatic imbalances) related to these low levels; and understand how primary care nurses looking after people with hypothyroidism are acting as external agents of homeostatic control.