Nurses Have Always Diagnosed: The Historical, Legal and Scientific Case for Nursing Engagement in Diagnosis

Aim To review the historical, legal, theoretical and evidentiary foundations for registered nurse engagement in diagnosis and to argue for systematic inclusion of nursing's diagnostic contributions in team‐based diagnosis. Background Diagnosis has been a constitutive element of nursing practice since the profession's earliest years, yet nursing's diagnostic authority has been persistently contested, constrained by legislation and rendered invisible in health information systems and diagnostic safety frameworks. Design Discursive paper. Methods Drawing on published research, regulatory and historical analysis, and interprofessional policy literature, the paper traces nursing's diagnostic role from early public health nursing through legislation, case law and standardized nursing language, and current evidence on diagnostic safety and education. Results Nursing diagnosis is not a novel aspiration or an expansion of scope but a documented feature of practice across more than a century; as Christman and Safriet argued, no discipline owns knowledge, and diagnostic language serves the patient, not professional territory. Team‐based diagnosis including nurses improves quality and reduces error, yet scope‐of‐practice barriers and a preparation‐to‐practice gap in clinical judgement constrain nursing's contribution. Conclusion Systematic inclusion of nursing's diagnostic contributions is essential to achieving high‐quality, equitable, team‐based diagnosis. Realizing this requires removing regulatory and structural barriers and strengthening nurses' preparation in clinical reasoning and diagnostic articulation. Implications for the Profession and/or Patient Care Making nursing's diagnostic work visible, standardized, and integrated into health information systems can strengthen diagnostic safety, support interprofessional collaboration and reduce diagnostic error. Impact Nursing is largely excluded from diagnostic frameworks despite nurses' proximity to patients. Its systematic inclusion improves diagnostic quality and safety. The findings are relevant to nurses, educators, regulators and health‐system leaders internationally. Reporting Method Not applicable; as a discursive paper, no EQUATOR reporting guideline applies. Patient or Public Contribution No patient or public contribution.