Asthma Symptoms, Causes, and Medications

A doctor looks at a chest X-ray of a patient with asthma.
A young girl uses an inhaler to treat her asthma.
An illustration shows the bronchiole tubes with normal airway passage.
The narrowing that occurs in asthma is caused by inflammation, bronchospasm, and hyperreactivity.
Asthma inflammation causes mucus to fill the bronchiole tubes, resulting in an obstructed airway.
An animated illustration shows the muscle constriction of the airways known as bronchospasm.
A smokestack emits greenhouse gases and irritants (left), pollen floats in the air (center) and a woman sneezes due to allergens (right).
Asthma triggers fall into two categories: allergens (specific) and nonallergens – mostly irritants (nonspecific).
Wind blowing pollen into the air (top left), a magnified image of a dust mite (top right), a dog and a cat (bottom left), and peanuts (bottom right) are examples of allergens that may cause asthma.
A woman suffering from a cold (top left), a bottle of antiinflammatory drugs (top right), cigarette smoke (bottom left) and exterminator spraying for insects in a kitchen (bottom right) are examples of asthma irritants.
A mother helps her daughter with an asthma inhaler.
A young girl with allergic asthma uses her asthma inhaler.
A woman with nonallergic asthma uses an asthma inhaler.
A man shows symptoms of wheezing, coughing, and chest tightness, signifying an asthma attack.
Asthma Classification Chart.
A man uses his asthma inhaler while experiencing an acute asthma attack.
A spirometer (left) and peak flow meter (right) are devices that test and measure lung functionality in asthma diagnosis.
A bronchodilator or metered-dose inhaler (left) and dry-powder  inhaler (right) may be used in the treatment of asthma.
A boy holds his asthma inhaler.

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Reviewed by William C. Shiel Jr., MD, FACP, FACR on Saturday, October 29, 2016

Asthma Symptoms, Causes, and Medications

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