Asthma is a chronic inflammatory disease that affects the lining of the airways.
The airways become swollen and narrowed and they produce extra mucus. Episodes of worsening asthma (called asthma attacks) occur when the narrowing worsens.
During an asthma attack, symptoms may range from mild wheezing (whistling or hissing sound as you breathe) to severe obstruction of the airways, potentially causing a life-threatening inability to breathe. Cough-variant asthma manifests as persistent, chronic cough without shortness of breath. Although asthma can be very serious, there are many ways to prevent and control symptoms.
The underlying cause of asthma is two-fold: 1) inflammation in the lining of the lung, and 2) structural changes in the lung due to inflammation and narrowing of air passages. Factors in the environment (both indoors and outdoors), called triggers, can make asthma symptoms worse and cause asthma attacks in people who have asthma.
Known asthma triggers include:
Asthma overview. American Academy of Allergy, Asthma, & Immunology website. Available at: http://www.aaaai.org/conditions-and-treatments/asthma.aspx. Accessed September 14, 2012.
Asthma. American Lung Association website. Available at: http://www.lung.org/lung-disease/asthma. Accessed September 14, 2012.
Asthma overview. Asthma and Allergy Foundation of America website. Available at: http://www.aafa.org. Accessed September 14, 2012.
Asthma in adults and adolescents. EBSCO DynaMed website. Available at: https://dynamed.ebscohost.com/about/about-us. Updated September 7, 2012. Accessed September 13, 2012.
Asthma exacerbation in adults and adolescents. EBSCO DynaMed website. Available at: https://dynamed.ebscohost.com/about/about-us. Updated August 27, 2012. Accessed September 13, 2012.
Understanding asthma. National Institute of Allergy and Infectious Diseases website. Available at: http://www.niaid.n.... Accessed September 13, 2012.
Last reviewed October 2012 by Brian Randall, MD
Last Updated: 10/11/2012