older people’s health issues
Changes in the Body With Aging
Lungs and the Muscles of Breathing
(See also Effects of Aging on the Respiratory System .) The muscles used in breathing, the diaphragm and muscles between the ribs, tend to weaken. The number of air sacs (alveoli) and capillaries in the lungs decreases. Thus, slightly less oxygen is absorbed from air that is breathed in. The lungs become less elastic. In people who do not smoke or have a lung disorder, these changes do not affect ordinary daily activities, but these changes may make exercising more difficult. Breathing at high altitudes (where there is less oxygen) may also be harder. The lungs become less able to fight infection, partly because the cells that sweep debris containing microorganisms out of the airways are less able to do so. Cough, which also helps clear the lungs, tends to be weaker. 