To develop a theoretical account of how palliative nurses can interpret residual symptom burden when complete symptom relief is either unattainable or conflicts with a goal that the patient values more highly. Original non-empirical theory development informed by palliative nursing theory, symptom-management scholarship, patient-preference research, goal-concordant-care literature and evidence concerning serious-illness decision-making. Peer-reviewed nursing, palliative-care and preference-sensitive-care literature published between 2017 and 2024 was critically selected to examine symptom experience, multidimensional assessment, treatment burden, functional priorities, clinician understanding of patient goals, temporal preference change and safety limits surrounding severe or refractory suffering. The analysis distinguishes incomplete symptom relief caused by ineffective or inadequate care from residual discomfort that a patient knowingly accepts because further relief would threaten cognition, meaningful activity, interaction, independence or another higher-priority goal. Patient-Defined Acceptable Discomfort Theory treats acceptability as relational, purpose-dependent, revisable and clinically bounded rather than as a numerical symptom threshold. Symptom intensity remains important, but it cannot independently establish whether care has achieved the patient’s goal. Palliative nursing requires a concept of successful symptom management that can accommodate both vigorous relief of unwanted suffering and carefully negotiated acceptance of some residual burden. Such acceptance is ethically and clinically defensible only when the patient’s priority is adequately elicited, feasible alternatives are considered, preferences remain revisable and unacceptable or refractory suffering is not relabelled as tolerable merely because complete relief is difficult.
