Bronchitis is a respiratory infection that affects your sinuses, nose, and throat. This infection spreads to your lungs. This can be viral infection that incorporates a bacterial infection. People who smoke a lot, who have heart and lung diseases, and who have weak immune systems (infants, children, and elder people) are very prone to acquiring this condition. If your mucus-filled cough lasts for at least 3 months, then that is usually diagnosed as chronic bronchitis. Bronchitis is a type of COPD or chronic obstructive pulmonary disease. This respiratory condition could worsen if the patient is exposed to allergens, air pollution, and other secondary infections. Some known symptoms of bronchitis are wheezing, shortness of breath, fever, fatigue, cough with yellow-green phlegm, and chest discomfort.