The effects of aging on the respiratory system are similar to those that occur in other organs: maximum function gradually declines. Age-related changes in the lungs include decreases in the peak airflow, gas exchange, and vital capacity (the maximum amount of air that can be breathed out following a maximum inhalation); weakening of the respiratory muscles; and a decline in the effectiveness of lung defense mechanisms. In healthy people, these age-related changes seldom lead to symptoms, but they can contribute to an older person's reduced ability to perform vigorous exercise, especially intense aerobic exercise, such as running, biking, and mountain climbing. Obesity also reduces pulmonary function. Additionally, older people are at higher risk of developing pneumonia after bacterial or viral infections. Thus, vaccines for respiratory infections such as influenza and pneumococcal pneumonia are particularly important for older people (see Viral Infections: Prevention and Bacterial Infections: Prevention). Importantly, age-related changes in the lungs compound the effects of heart and lung diseases the person may have, especially those caused by the destructive effects of smoking.

Last full review/revision August 2006 by Joseph D. Brain, ScD