The physiology of ageing

Normal ageing is responsible for the finite life-span of the human race. It is important for the doctor treating the elderly to know the difference between changes secondary to normal ageing and changes which occur as a result of disease. There is ongoing research to increase our knowledge on the ageing process. Age-related physiological decline results in defective homeostasis responsible for the susceptibility of the individual to succumb in minor stresses. Knowledge of physiological decline in the various organs has clinical implications in the interpretation of physiological tests, especially when the organ systems are stressed, in the need to adjust dosage of drugs given to the elderly and in the understanding of some atypical presentations of illness in the elderly.