What Causes Bronchitis?
The bronchial tubes, or bronchi, connect the windpipe to the lungs. When the lining of the bronchial tubes becomes inflamed or infected, the condition is called bronchitis. Bronchitis reduces the amount of air and oxygen that can flow into the lungs and causes a heavy mucus or phlegm to form in the airways. Bronchitis is considered to be acute or chronic. Acute bronchitis is a shorter illness that commonly develops after a cold or viral infection such as the flu. It generally consists of a cough with green sputum, chest discomfort or soreness, fever, and sometimes shortness of breath. Acute bronchitis usually lasts a few days or weeks. Chronic bronchitis is characterized by a persistent, mucus-producing cough on most days of the month, three months of a year for two successive years in absence of a secondary cause of the cough. People with chronic bronchitis have varying degrees of breathing difficulties, and symptoms may get better and worsen during different parts of the year.