The lower part of the respiratory system consists of the trachea, which divides into the two main bronchi and then into smaller air passages, and the lungs. The lungs can be damaged by many factors, such as inhaled smoke and dust, infections, and allergies. The resulting disorders vary in severity from mild conditions, such as a cough, to life-threatening illnesses, such as lung cancer.
This section starts with two common symptoms, cough and hiccups. More serious disorders of the airways are discussed next, including asthma, a common long-term disorder in developed countries.
Many common lung diseases, such as pneumonia and tuberculosis, are caused by infections. After discussion of these disorders, articles follow on disorders of the pleura. Occupational lung diseases are then covered.
The next article discusses primary lung cancer, one of the most common types of cancer in the world and the most likely to prove fatal. Lung cancer is almost always caused by smoking. The final articles cover acute, potentially life-threatening lung disorders, such as acute respiratory distress syndrome.
Lung diseases specific to children are dealt with elsewhere (see Infancy and childhood).
For more information about the structure and function of the lungs, see Steam Inhalation.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.