Historical milestones in basic research on aging include (1) the demonstration that caloric res-triction (CR) increases average and maximum lifespan in rodents; (2) the proposal that oxidative stress is a major risk factor in the development of age-related pathology; and (3) the demonstration that human fibroblasts grown in culture have a finite lifespan. Thus, although research related to aging has been going on for well over 50 years, particularly on the age-related pathologies associated with aging, serious efforts to understand what factors modulate longevity are fairly new, and progress in this area is due primarily to the identification of genes that modulate longevity in short-lived animal models. Prior to 1980, the main focus was on describing aging phenomena in humans and rodents, and testing the various theories of aging resulting from these early observations. As the techniques of molecular biology were increasingly incorporated into aging-related research, it became possible to ask more mechanistic questions, and considerable progress was made during the period 1980–2000, largely because of the development of short-lived fruit fly and nematode models in which to study aging, followed by the sequencing of the genomes of these organisms. For example, this work quickly led to the discovery that the insulin-signalling pathway plays a major role in modulating longevity, not only in these organisms, but also in rodents and probably primates.

The human lung is a resilient and complex organ, capable of uninterrupted functioning without defect over a lifetime. While there is a body of knowledge regarding macroscopic and physiological changes that occur in the lung with age, there is still much to be understood. In itself this is not surprising given the complex interaction of intrinsic and extrinsic factors that might play a role in these changes. Lung tissue is highly susceptible to environmental factors, which can have an impact over the course of a lifetime, including smoking, pollutants, occupation and nutrition.

Peripheral neuropathy encompasses disorders of the peripheral nervous system, affecting the axon and/or the myelin sheath. The prevalence of peripheral neuropathy increases with age. Thought to be of about 3000 per 100 000 in adults generally, this figure could be as high as 8000 above the age of 60 years. However more than half of these cases would be due to impaired glucose metabolism in its various forms. In the remainder, an aetiology may be found in about 70% of cases. The elderly population is at higher risk of peripheral neuropathy, as there is a correlation between age and impairment of the peripheral nervous system. The natural aging process affects adversely the function of peripheral nerves and of their target organs, resulting in the development of motor, sensory and autonomic symptoms in the absence of additional damage of other causes. In addition, the increased prevalence of chronic systemic disorders causing neuropathy, as well as the use of neurotoxic drugs in older patients, contribute to the onset of neuropathy.

Age has been identified as the single most impor-tant demographic predictor of blindness and visual impairment. Visual impairment is the second most prevalent physical disability in the elderly population. The prevalence of blindness and visual impairment after 60 years of age increases significantly. Furthermore, the number of older people with functional vision impairment is expected to double in the next decade. Visual impairment in the elderly population is commonly due either to localized ocular pathology (cataracts, glaucoma and age-related macular degeneration) or systemic disease with associated ocular or visual pathway involvement (hypertension, diabetes and cerebrovascular disease). Physicians involved in the care of older people play a crucial role in the recognition, prevention and management of morbidity related to visual impairment in this population. Timely screening, referral, intervention and visual rehabilitation is thought to be capable of reducing new blindness and visual impairment by at least one-third.

The World Health Organization's definition of anaemia is a haemoglobin level of less than 13g/dL for men and less than 12g/dL for women. Haemoglobin levels have been shown to decline with age, making anaemia a relatively common problem among older people. Because of this fall in haemoglobin with age, there has been some debate about whether an age-related reference range should be used. However, most clinicians believe that, because of the association between anaemia and increased risk of morbidity, mortality and hospitalization, the normal haemoglobin range should not be lowered for older people.

In the past, most amputees have been veterans of war or other younger people who have sustained traumatic injury. There are now an increasing number of older people undergoing lower-limb amputation, most commonly because of vascular problems. Anecdotal evidence suggests that there is a lack of support for patients facing limb amputation, and a lack of recognition from staff that these patients may be at risk of ongoing psychological problems following the procedure.