A brief review of changes in the morphology, physiology and defence mechanism in the ageing lung is presented. During the ageing process, the lung is also affected by environmental insults, which can be exogenous or endogenous. Exogenous factors include infection, climate, air pollution and mechanical injuries, whereas endogenous environments are certain system diseases (e.g. diabetes mellitus and thromboembolism) as well as infectious diseases (e.g. tuberculosis).
