General Practice 2 Handbook 2021/22

The diagram displays the various elements of the consultation, highlighting the importance of going beyond “getting the history” and integrating the medical and patient-specific aspects of the consultation. The shaded boxes are based on the “illness/disease” model proposed by Stewart et al. The bold outlined boxes relate to the tasks and skills defined by Silverman et al in the Cambridge/Calgary observation guide – which forms the basis of most OSCE (Objective Structured Clinical Examinations) exams for undergraduates.  

Disease versus Illness These two words are often used interchangeably in the English language but have assumed subtly different meanings which form the basis of the model of the consultation above.   

Disease is the medical view of ill-health. It is based mainly on objectively demonstrable changes in the body’s structure or function, and which can be quantified by reference to ‘normal’ physiological measurements. They include, for example, typical symptom clusters (such as, in migraine) abnormal physical findings (e.g., irregular heartbeat), abnormal test results (e.g., raised white cells or TSH in the blood or an enlarged heart on an echo). Disease ‘entities’ (such as Tuberculosis) are assumed to be universal in form, content, clinical findings, natural history, and treatment. 

Illness is the subjective response of the patient, and those around him (or her), to being unwell. Particularly how he/she, and they, interpret the origin and significance of this event; how it affects his/her behaviour, and his/her relationships with other people and the steps taken to remedy the situation. It includes both his/her experience of ill-health, and the meanings given to that experience. Illness experience is shaped by how he/she answers the questions listed in Helman’s Explanatory Model (below) and is often expressed in the form of a narrative or personal story. 

In most cases people have a disease and an illness at the same time. For example, they may feel unwell – and also have a chest infection. However, in clinical practice it is also possible to encounter ‘disease without illness’ (e.g., asymptomatic diabetes, cancer or HIV infection), and also ‘illness without disease’ (e.g., fearfulness) – but without any discernible physical abnormality. Functional disorders such as irritable bowel syndrome form a sort of hybrid and remember over 20% of all presentations in primary and secondary care remain unexplained. In all cases, difference in interpretations may result in communication difficulties between doctor and patient.