Childhood adversity alters the relational world of the child and inhibits the development of secure attachment bonds. The purpose of this article is to survey recent evidence that attachment insecurity has the potential to impair physical health throughout the lifespan. It is proposed that attachment insecurity contributes to disease risk through a range of mechanisms which include (1) disturbances in arousal and recovery within physiological systems that respond to stress; (2) physiological links between the mediators of social relationships, stress, and immunity; (3) links between relationship style and various health behaviors; and (4) disease risk factors that serve as external regulators of dysphoric affect, such as nicotine and alcohol. The evidence for these mechanisms, particularly the evidence that has accumulated since the model was first proposed in 2000, is presented and discussed.