Making Respiratory Medicine Visible: Intralingual and Multimodal Mediation in Academic and Institutional Health Videos

Audiovisual health communication must preserve terminological accuracy while making complex physiological processes intelligible to viewers with different levels of medical knowledge. This article presents a comparative multimodal case study of four English-language audiovisual resources produced or hosted in British healthcare and academic contexts, organised into two academic–institutional pairs: the International Primary Care Respiratory Group’s How We Breathe and the NHS animated video Asthma; and Peter Barnes’s HSTalks lecture COPD and Asthma: Similarities and Differences and Blackpool Teaching Hospitals’ Symptoms of COPD. The analysis examines how spoken explanation, curated intralingual captions or subtitles, on-screen written labels, animation, slides, emphatic gestures, temporal organisation, and audience positioning jointly mediate respiratory knowledge. It combines close linguistic analysis with speech–caption, temporal, and visual annotation. The findings indicate that accessibility is not achieved primarily through the removal of specialist terminology. Instead, the resources deploy different combinations of dual-register mediation, selective terminological retention, contrastive visual architecture, causal compression, segmentation, and cross-modal access. The comparison thus distinguishes information reduction from lexical simplification and proposes mediation density and causal resolution as qualitative parameters for analysing audiovisual medical accessibility. On this basis, the study advances a context-sensitive account of accessibility grounded in the distribution of explanatory work across modes. It also demonstrates the value of treating intralingual captions as one component of a wider multimodal communicative design rather than as the sole site of intralingual translation.