Lung disease is any disease or disorder where lung function does
not work properly. There are three main types of lung disease:
Obstructive lung disease -- a decrease in the exhaled
air flow caused by a narrowing or blockage of the airways,
which can occur with
asthma,
emphysema, and
bronchitis.
Restrictive lung disease -- a decrease in the total
volume of air that the lungs are able to hold. Often, this
is due to a decrease in the elasticity of the lungs
themselves or caused by a problem related to the expansion
of the chest wall during inhalation.
A defect in the ability of the lung's air sac tissue to
move oxygen into a person's blood.
Most lung diseases actually involve a combination of these
categories, such as emphysema, which involves both airflow
obstruction and oxygenation problems.