The iceberg of illness¹ is an important concept in understanding the relation between health and illness and one that healthcare systems ignore, Titanic-like, at their peril. The pyramidal iceberg has health at its base and tertiary care at its apex; as individuals develop symptoms they pass upwards through self care, primary care, and secondary care, with specialised services encountering an ever more highly selected patient population. We know surprisingly little about what prompts movement across these interfaces, particularly that between self care and primary care. Initiatives within the NHS to make access to services easier could have profound effects, yet the necessary research is only just being defined.

The movement of patients from self care to primary care and from primary to secondary care determines workload for health services, and relatively small changes at the base of the pyramid can have substantial impacts on demand at higher levels. For example, population screening, ascertainment by case finding, and genetic testing may all substantially increase the movement of people across the self care-primary care interface. As well as impacting on the use of resources, the quality of self care is important for the quality of life of individuals who deal with their symptoms without seeking formal medical advice.

Diary studies suggest that as few as one in 40 symptoms ever reaches a medical consultation.^2,3 Population surveys have shown that common gastrointestinal symptoms, such as rectal bleeding, irritable bowel syndrome, and dyspepsia are present in 15-40% of the general population but that only a quarter to a third of these people seek medical advice about them.⁴ The reasons for doing so are complex and include severity of symptoms, their impact on quality of life, other events in patients' lives, and patients' health beliefs.⁵ Patients obtain information about their symptoms from a range of sources, although little systematic research has been carried out on the factors which inform healthcare seeking decisions.

Self care is, of course, not only important at the lay-professional interface but permeates the health system. Concepts such as patient enablement⁶ and the concordance model of doctor-patient interaction⁷ have been developed recently. Self care is also an essential component of the management of chronic illness.

Recent policy developments, mostly centred around the desire to improve access, may have begun to tilt the balances across some of these interfaces. Walk-in medical centres, direct access telephone lines (such as NHS Direct), and other alternatives to traditional primary care require careful evaluation, not just in terms of their immediate benefits to patients but in relation to longer term and more subtle changes in healthcare seeking behaviour. For example, the gatekeeper function of primary care, controlling access to expensive and invasive secondary care services, is an important component of a cost effective health service.⁸ The erosion of personal primary care in recent years, augmented by well intentioned initiatives to improve access, might well lead to escalating and inappropriate use of precious resources. Persuasive arguments for better access to services⁹ need to be tested against an analysis of the costs as well as benefits of new arrangements.

A large research agenda surrounds self care, which begins with the need to understand patients' constructions of symptoms and disorders, particularly when different cultural contexts may lead to dramatically different responses to illness. We need to have a better understanding of patients' needs and expectations of health advice and care, of the best ways of providing information to enable people to deal with their health concerns themselves, and of ways to help them to use services most effectively. Research into the efficacy of self help information about minor illness and common symptoms needs to be extended to examine the value of better targeted and more sophisticated sources of information, including interactive communication.

The response of primary care professionals to patients with common, minor illnesses is itself a determinant of subsequent patterns of healthcare seeking behaviour.¹⁰ More research is needed to guide practitioners towards the optimum ways of configuring services, interacting with patients, and providing drug and non-drug solutions to illness. The role of lay people and professionals in providing this advice requires further study, and, in particular, the emerging role of the community pharmacist as a source of advice about acute and chronic conditions needs further research. Such research is likely to be focused at the interface between self care and primary care and will require imaginative research methods and collaboration between clinicians, other healthcare professionals, and behavioural and social scientists. A welcome initiative is the recent establishment by the Proprietary Association of Great Britain (www.pagb.org.uk) of a fund to support research in this subject.