The majority of older people remain in good health until a relatively short period before their death. Most of those who acquire chronic illness tend to have only mild to moderate disability and are not dependent on others for life’s basic tasks. Common chronic diseases associated with mild disability include arthritis, hypertension, ischaemic heart disease and diabetes mellitus.

However, the minority of older people who have chronic illness associated with severe disability have a large impact on our healthcare and welfare systems. Depression, Alzheimer’s disease and other dementias, stroke with residual disability, and various progressive neurological disorders contribute greatly to the overall burden of disability experienced by our society. Although circulatory, neoplastic and respiratory diseases are the most common causes of death, nervous-system disorders contribute the greatest proportion of years of life lost to disability in the older population.1 Disability-adjusted life-years (DALYs), which combine the effects of shortened life expectancy and years lost to disability, enable an assessment of the overall burden of illness. In terms of DALYs, ischaemic heart disease and stroke rank first and second, respectively, in both sexes, followed by lung cancer in men and dementia in women.1

While the experience of chronic illness is different for each individual, its impact may be experienced in two broad dimensions, depending on the nature of the illness and the type of disability it produces.

The patient may experience predominantly somatic symptoms, such as dyspnoea, pain, weakness, lethargy or nausea. The resulting discomfort interferes with enjoyment of life. Many people with conditions such as cardiac, respiratory and neoplastic disorders may remain relatively independent, at least in the confines of their own home, until late in the progression of the illness. However, they live with the constant threat of exacerbation and associated visits to hospital, and uncertainty about their life expectancy. Our challenge with these patients is to ameliorate distressing symptoms, halt progression of the disease, and prevent complications and unnecessary hospital admissions.

On the other hand, the patient experience may be dominated by disability and handicap. Patients in this situation become distressed by their lack of independence in various life skills, which ultimately reduces their ability to survive in their “usual” living environment. Chronic conditions such as stroke and degenerative neurological disorders cause profound disturbances of personal functioning that increase as the illness progresses, such that dependence on others becomes continuous. Basic tasks such as walking, bathing, dressing and feeding become impaired. The situation is exacerbated by the presence of cognitive dysfunction. Ultimately, survival at home is dependent on the support of family members, often with the assistance of community services. It is these illnesses that drive the demand for nursing home places. Some 70% of residents of nursing homes have moderate to severe cognitive impairment.

These clinical scenarios highlight the predicament that faces all societies as the proportion of older people increases. With smaller families, and greater numbers of people entering old age either divorced or never married, there is a considerable challenge to provide the care that is so vitally needed. The paucity of family-member carers will be accompanied by declining numbers of people in the workforce. Similarly, the number of taxpayers who provide funds for care will decline in relation to those requiring it.2

Ultimately, the challenge will be to minimise the period of discomfort and dependence on others towards the end of life. This will require advances in prevention, management of disability and technology to reduce the reliance on others. It will also require robust social service support networks and public utility infrastructure that are sensitive to the needs of elderly people and provide adequate high-quality residential care for people who can no longer live independently.