BACKGROUND:Patient experience is recognised as a means of assessing healthcare delivery with organisations in many countries now gathering patient experience or satisfaction data. It is well documented that the benefits of improving a patients' experience include increased satisfaction, reduced length of stay, improved patient outcomes and reduction of costs. The experience of acute clinical deterioration is unique, extensive and complex as well as being a difficult experience for all involved. However, little is known about this experience from the patient's perspective. AIM:To explore what is known about the experiences of acute deterioration from the perspective of the patient. DESIGN:A scoping review of international, peer-reviewed research studies and grey literature published between the years of 2000 and 2018. This review was guided by the three-step search strategy recommended by the Joanna Briggs Institute (JBI). DATA SOURCES:A range of databases were searched, including CINAHL, Medline, Health Source, Joanna Briggs Institute, PsycINFO, Embase via Ovid, Cochrane library, Ovid Emcare, Scopus as well as grey literature, reference lists and the search engine Google Scholar. REVIEW METHODS:Joanna Briggs Institute (JBI) scoping review framework was utilised to identify patients' experiences of acute deterioration. Ten databases were searched, and 249 articles were retrieved. After screening the titles and abstracts, 102 articles were assessed in full text for eligibility, and finally 23 articles were further analysed and synthesised using inductive thematic analysis. RESULTS:19 qualitative studies, three quantitative and one mixed methods study met the inclusion criteria. Seven key themes emerged related to patients' experience of acute deterioration: (1) transformation of perception: memories of factual events; (2) psychological transformation: emotional distress and well-being; (3) physiological transformation: physical distress; (4) facing death; (5) the severity of acute deterioration: from the perspective of the patient; (6) relationship with healthcare professionals and the clinical environment; and (7) the value of relationships: the support of family and friends. CONCLUSIONS:Participants had considerable recall of their experiences and hospital admissions. The themes highlight the important issues patients face during their own acute physiological deterioration. This review has highlighted that further research is needed to specifically explore the patients' experience of acute deterioration and the emergency management they receive, for example from a hospital's rapid response team (RRT) or medical emergency team (MET).