Britannica
Sources used in this answer
Why might severe bronchitis cause large amounts of sputum in the morning?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
respiratory disease
The bronchioles of the lungs are the site where oxygen is exchanged for carbon dioxide during the process of respiration. Inflammation, infection, or obstruction of the bronchioles is often associated with acute or chronic respiratory disease, including bronchiectasis, pneumonia, and lung abscesses.
In severe bronchitis, the production of large amounts of sputum in the morning occurs primarily because the mucous glands lining the bronchi become significantly enlarged and increase in number. These hypertrophied glands secrete excessive amounts of viscous fluid into the airways.123
During the night, this mucus accumulates in the bronchial tree. Consequently, when a patient awakens, they typically experience a productive cough as the body works to clear the buildup that gathered while they were inactive. This symptom is a hallmark of chronic bronchitis, a condition often caused by long-term exposure to tobacco smoke or other environmental irritants, which leads to permanent damage and inflammation of the bronchial walls.123