This dissertation contains a modified Walker and Avant (2005) concept analysis on caregiver reactions, a review of empirical referents, and a qualitative phenomenological investigation into informal caregiver reactions in pulmonary hypertension (PH). In the second chapter, the assumption of burden in caregiving is a presupposition, so the importance of bracketing and inclusion of positive reactions in caregiving is highlighted in the concept analysis. This chapter further identified and determined the defining attributes of informal caregiver reactions, as well as antecedents and consequences. A model case is also presented. Chapter three reviews the Bakas Caregiving Outcomes Scale (BCOS), the Caregiver Reaction Assessment (CRA), the Modified Caregiver Strain Index (MCSI), the Zarit Burden Interview (ZBI), the Perceived Caregiver Burden Scale (PCBS), the Multidimensional Caregiver Burden Inventory (MCBI), and the Screen for Caregiver Burden (SCB)