1.34. Respiratory System Diseases http://www.ck12.org
This inhaler can help ease the symptoms of asthma. The boy may have felt an asthma attack coming on. Tightness
in his chest and difficulty breathing are common signs of an asthma attack. He is fortunate that asthma can usually
be controlled with medicine.
Diseases of the Respiratory System
Respiratory diseases are diseases of the lungs, bronchial tubes, trachea, nose, and throat (Figure1.60). These
diseases can range from a mild cold to a severe case of pneumonia. Respiratory diseases are common and may
cause illness or death. Some respiratory diseases are caused by bacteria or viruses, while others are caused by
environmental pollutants, such as tobacco smoke. Some diseases are genetic and, therefore, are inherited.
FIGURE 1.60
This boy is suffering from whooping cough (also known as pertussis),
which gets its name from the loud whooping sound that is made when
the person inhales during a coughing fit.Bronchitis
Bronchitisis an inflammation of the bronchi, the air passages that conduct air into the lungs. The bronchi become
red and swollen with infection. Acute bronchitis is usually caused by viruses or bacteria, and may last several days
or weeks. It is characterized by a cough that produces phlegm, or mucus. Symptoms include shortness of breath and
wheezing. Acute bronchitis is usually treated with antibiotics.
Asthma
Asthmais a chronic illness in which the bronchioles, the tiny branches into which the bronchi are divided, become
inflamed and narrow (Figure1.61). The muscles around the bronchioles contract, which narrows the airways. Large
amounts of mucus are also made by the cells in the lungs. People with asthma have difficulty breathing. Their chests
feel tight, and they wheeze.
Asthma can be caused by different things, such as allergies. Asthma can also be caused by cold air, warm air, moist
air, exercise, or stress. The most common asthma triggers are illnesses, like the common cold.
Asthma is not contagious and cannot be passed on to other people. Children and adolescents who have asthma can
still lead active lives if they control their asthma. Asthma can be controlled by taking medication and by avoiding
contact with environmental triggers for asthma, like smoking.