Scores of published studies support the general conclusion that illness and disability have negative effects on the emotional and physical well-being of family caregivers, and while the notion of suffering may be implicit in existing conceptualizations of illness and disability, the empirical research has not focused on patient suffering as a unique and independent contributor to caregiver outcomes (Schulz et al, 2007). The proposed research will focus on the manifestation of suffering in care recipients with musculoskeletal conditions, specifically individuals with osteoarthritis and lower back pain, and the ways suffering impacts on spousal caregivers. We focus on care recipients and their spousal caregivers, because spouses of care recipients are likely to be faced with acute instances of the care recipient's pain and suffering on a daily basis (e.g. when they are performing everyday household activities). We operationalize caregivers1 exposure to the suffering in two ways in a laboratory setting: (1) observing expressed pain from the care recipient who is performing a simulated household task and (2) preparing a speech about the care recipient's suffering. We also ask all participants to complete self-report measures of the care recipients'suffering in everyday life that incorporate questions about the physical, psychological, and spiritual/existential components of suffering. We propose that the caregiver's exposure to suffering can lead to a heightened cardiovascular stress response, operationalized as increased blood pressure (BP) and heart rate (HR), and low heart rate variability (HRV). We also propose that the caregiver's exposure to the care recipient's suffering will result in the psychological experience of personal distress and/or empathic concern, which will be highly interrelated with the cardiovascular stress response. Furthermore, we explore how factors associated with the care recipient, the caregiver, and the relationship impact caregiver's psychological and physiological reactions to the care recipient's suffering. For example, we test the hypothesis that witnessing a spouse in pain will lead to a high heighten to provide crucial information about susceptibility to cardiovascular disorders (e.g., coronary heart disease and hypertension) for older Americans. Also, because we are investigating differences in cardiovascular reactions to witnessing relationship partners and strangers'suffering, this research has implication not only for family caregivers, but also for professional helpers (nurses, doctors, teachers, and therapists).