ABSTRACT
A healthy person functions well in both bodily activity and social relationships; conversely, an unhealthy person is likely to have altered personal relationships. The gradual deterioration of function with increasing age is so widely perceived and so expected that all deterioration in function in an elderly person tends to be attributed to age. Disease in younger adults usually produces characteristic symptoms and signs by which a particular disease is recognised; if a diagnosis is not achieved on initial contact with the patient, the symptoms and signs are used as a base for further investigations and action. Functional disability due to disease attracts little medical interest, which is concentrated upon the specific features of the disease; thus the referral letter about a younger patient with suspected myocardial infarction is likely to discuss the features of the chest pain, but is unlikely to mention whether the patient can walk to the toilet or feed himself.
