Grief encompasses emotional, behavioral, cognitive, and physical responses to a loss. Western notions of grief have been heavily influenced by a medical model that views grief as a form of illness in need of intervention, although no clear consensus exists on what constitutes normal versus abnormal grief. Societal norms and rules prescribe how a bereaved individual is expected to feel, think, and behave, shaping individual experiences of grief. Culturally based grieving rules govern what losses can be legitimately grieved, by whom and for how long, and how others should respond. Experiences falling outside these rules are disenfranchised. The type of loss experienced and the social characteristics of the bereaved also influence the experience of grief. A plethora of theories on grief exist with notable shifts over time. Collective experiences of grief are also investigated at the family and community level.