The death of a loved one is recognized as one of life's greatest stresses, with reports of increased mortality and morbidity for the surviving spouse or parent, especially in the early months of bereavement. The aim of this paper is to review the evidence to date to identify physiological changes in the early bereaved period, and evaluate the impact of bereavement interventions on such physiological responses, where they exist. Research to date suggests that bereavement is associated with neuroendocrine activation (cortisol response), altered sleep (electroencephalography changes), immune imbalance (reduced Tlymphocyte proliferation), inflammatory cell mobilization (neutrophils), and prothrombotic response (platelet activation and increased vWF-ag) as well as hemodynamic changes (heart rate and blood pressure), especially in the early months following loss. Additional evidence suggests that bereavement interventions have the potential to be of value in instances where sleep disturbance becomes a prolonged feature of complicated grief, but have limited efficacy in maintaining immune function in the normal course of bereavement.