Coughing
Coughing is a reflex action that occurs when irritants invade the respiratory tract or when excessive secretions accumulate in the lungs. This process begins with the stimulation of nerves in the larynx, trachea, and bronchial tubes, resulting in increased pressure in the chest cavity. The glottis, or opening of the windpipe, temporarily closes to build this pressure before suddenly opening to expel air and foreign substances, such as mucus. Coughing serves as a critical symptom for various respiratory conditions affecting the nasal cavities, throat, larynx, trachea, bronchi, and lung tissue.
The production of sputum, primarily composed of mucus, can indicate underlying diseases like bronchitis, while the presence of blood in the sputum calls for immediate medical attention, as it may hint at serious conditions such as tuberculosis. Environmental factors, including air pollution from vehicle exhaust and chemical fumes, can exacerbate respiratory issues and contribute to chronic bronchitis. Treatments often involve the use of antibiotics, anti-inflammatory medications, and strategies to improve air quality, such as employing air filters or inhalers. Understanding the mechanisms and implications of coughing can help in recognizing and addressing underlying health concerns.
On this Page
Subject Terms
Coughing
Anatomy or system affected: Chest, immune system, lungs, respiratory system
Definition: A physiological act in which air is forcibly expelled from the lungs
Causes and Symptoms
The energy that is consumed during the breathing process is used to stretch the chest cavity and allow air to flow into the lungs. This amounts to about 1 percent of the basic energy requirements of the body but increases considerably during periods of exercise or respiratory system illness.
When the respiratory tract is invaded by irritants (such as smoke, perfume, and pollen) or there is an excessive accumulation of secretions in the lungs, coughing takes place. It arises via a reflex mechanism that starts with the stimulation of the nerves that supply the larynx, trachea (windpipe), and bronchial tubes. The pressure within the chest cavity is increased by the action of chest muscles and the diaphragm. The glottis, the opening of the windpipe at the back of the mouth, remains closed in order to allow the pressure to rise. Within a few seconds, the glottis opens again and a rapid, noisy release of air is allowed through the bronchial tubes and the windpipe. Any foreign substance is expelled through the mouth.
Treatment and Therapy
Coughing is an important symptom of diseases that affect any part of the respiratory system, such as the nasal cavities, the pharynx (throat), the larynx, the trachea, the bronchi, and lung tissue. By coughing, foreign matter called sputum, which is chiefly composed of mucus that has accumulated in the respiratory system, is expectorated. Sputum formation during coughing is an important evidence of a disease, such as bronchitis. In this case, the lining of the bronchi enlarges dramatically and sputum production may increase to 60 milliliters per day. An irritative cough without sputum may be due to the extension of the disease to the bronchial tube and eventually to nearby organs. The use of antibiotics and anti-inflammatory agents to reduce the discomfort is part of the standard treatment.
The presence of blood in the sputum (called hemoptysis) is important and should alert patients or their caregivers to call a doctor. This symptom often arises from an existing infection, inflammation, or tumor. It is also a sign of tuberculosis. In this case, extensive and reliable tests will identify the real cause of the bleeding.
Polluted air increases the possibility of chronic bronchitis. Common air pollutants include vehicle exhaust, chemical fumes, smoke, smog, molds, and pollen. They are all responsible for a decrease in arterial oxygen and an increase in carbon dioxide tension in the lungs. The use of air-conditioning, air filters, and inhalers and an increased-oxygen environment can provide relief for people with respiratory problems.
Bibliography
Adelman, Daniel C., et al., eds. Manual of Allergy and Immunology. 5th ed., Wolters Kluwer, 2015.
Braga, Pier Carlo, and Luigi Allegra, eds. Cough. Raven Press, 1989.
Chung, Kian Fan, John G. Widdicombe, and Homer A. Boushey, eds. Cough: Causes, Mechanisms, and Therapy. Blackwell, 2008.
"Cough." Mayo Clinic, 13 June 2020, www.mayoclinic.org/symptoms/cough/basics/definition/sym-20050846. Accessed 15 July 2023.
Glenn, Jim. Colds and Coughs. Springhouse, 1986.
Kimball, Chad T. Colds, Flu, and Other Common Ailments Sourcebook. Omnigraphics, 2001.
Korpás, Juraj, and Z. Tomori. Cough and Other Respiratory Reflexes. S. Karger, 1979.
"What Is Cough?" National Heart, Lung, and Blood Institute, 1 Oct. 2010.
Woolf, Alan D., et al., eds. The Children’s Hospital Guide to Your Child’s Health and Development. Perseus, 2002.