respiratory system diseases

causes of respiratory diseases

Many respiratory diseases are caused by pathogens. A pathogen is an organism that causes disease in another organism. Certain bacteria, viruses, and fungi are pathogens of the respiratory system. The common cold and flu are caused by viruses. The influenza virus that causes the flu is pictured below ( Figure 1.6). Tuberculosis, whooping cough, and acute bronchitis are caused by bacteria. The pathogens that cause colds, flu, and TB can be passed from person to person by coughing, sneezing, and spitting. Illnesses caused by bacteria can be treated with antibiotics. Those caused by viruses cannot. Pollution is another common cause of respiratory disease. The quality of the air you breathe can affect the health of your lungs. Asthma, heart and lung diseases, allergies, and several types of cancers are all linked to air quality. Air pollution is not just found outdoors; indoor air pollution can also be responsible for health problems. Smoking is the major cause of chronic respiratory disease as well as cardiovascular disease and cancer. Exposure to tobacco smoke by smoking or by breathing air that contains tobacco smoke is the leading cause of preventable death in the United States. Regular smokers die about 10 years earlier than nonsmokers do. The Centers for Disease Control and Prevention (CDC) describes tobacco use as "the single most important preventable risk to human health The lung of a smoker who had emphysema (left). Tar, a sticky, black substance found in tobacco smoke, is evident. Chronic obstructive pulmonary disease (right), is a tobacco-related disease that is characterized by emphysema. This represents the influenza virus that causes the swine flu, or H1N1. The Center for Disease Control and Prevention recommends that children between the ages of 6 months and 19 years get a flu vaccination each year. in developed countries and an important cause of [early] death worldwide." Simply stated: Stopping smoking can prevent many respiratory diseases.




Emphysema is a chronic lung disease caused by the breakdown of the lung tissue. Symptoms of emphysema include shortness of breath, especially during exercise, and chronic cough, usually due to cigarette smoking, and wheezing, especially during expiration. Damage to the alveoli ( Figure 1.5), is not curable. Smoking is the leading cause of emphysema.

lung cancer

Lung cancer is a disease in which the cells found in the lungs grow out of control. The growing mass of cells can form a tumor that pushes into nearby tissues. The tumor will affect how these tissues work. Lung cancer is the most common cause of cancer-related death in men, and the second most common in women. It is responsible for 1.3 million deaths worldwide every year ( Figure 1.4). The most common symptoms are shortness of breath, coughing (including coughing up blood), and weight loss. The most common cause of lung cancer is exposure to tobacco smoke. The inside of a lung showing cancerous tissue.



Tuberculosis (TB) is a common and often deadly disease caused by a genus of bacterium called Mycobacterium. Tuberculosis most commonly attacks the lungs but can also affect other parts of the body. TB is a chronic disease, but most people who become infected do not develop the full disease. Symptoms include a cough, which usually contains mucus and coughing up blood. The TB bacteria are spread in the air when people who have the disease cough, sneeze, or spit, so it is very contagious. To help prevent the spread of the disease, public health notices, such as the one pictured below ( Figure 1.3), remind people how to stop the spread of the disease. A public health notice from the early 20th century reminded people that TB could be spread very easily.



Pneumonia is an illness that occurs when the alveoli, the tiny sacs in the lungs where gas exchange takes place, become inflamed and filled with fluid. When a person has pneumonia, gas exchange cannot occur properly across the alveoli. Pneumonia can be caused by many things. Infection by bacteria, viruses, fungi, or parasites can cause pneumonia. An injury caused by chemicals or a physical injury to the lungs can also cause pneumonia. Symptoms of pneumonia include cough, chest pain, fever, and difficulty breathing. Treatment depends on the cause of pneumonia. Bacterial pneumonia is treated with antibiotics. Pneumonia is a common illness that affects people in all age groups. It is a leading cause of death among the elderly and people who are chronically and terminally ill.



Asthma is a chronic illness in which the bronchioles, the tiny branches into which the bronchi are divided, become inflamed and narrow ( Figure 1.2). 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.


Bronchitis is 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.

diseases of the respiratory system

Respiratory diseases are diseases of the lungs, bronchial tubes, trachea, nose, and throat ( Figure 1.1). These diseases can range from a mild cold to a severe case of pneumonia. Respiratory diseases are common. Many are easily treated, while others may cause severe 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. 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.


instructional diagrams

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the common cold and flu are respiratory illnesses caused by viruses.

-->  a. true

b. false

stopping smoking can prevent many respiratory diseases.

-->  a. true

b. false

which disease is due to fluid in the alveoli of the lungs?

a) bronchitis

b) asthma

-->  c) pneumonia

d) tuberculosis

which disease is characterized by coughing up blood?

-->  a) tuberculosis

b) pneumonia

c) cancer

d) emphysema

which of the following causes asthma?

a) warm air, cold air, or moist air

b) allergies

c) exercise

-->  d) all of the above can cause asthma.

which respiratory disease is characterized by the breakdown of lung tissue?

a) pneumonia

b) tuberculosis

-->  c) emphysema

d) lung cancer

which two severe respiratory illnesses are caused mainly by smoking?

a) lung cancer and bronchitis

-->  b) lung cancer and emphysema

c) asthma and emphysema

d) emphysema and bronchitis

diagram questions

No diagram questions associated with this lesson