Cough is considered as the first symptom of COPD. Chronic bronchitis is diagnosed if your cough persists for three months or longer out of a year for at least two years.
A cough is a response to excess mucus production in which body removes mucus and clears other secretions from the lungs. These irritants and mucus can otherwise cause lung infections
Mucus is often pale yellow in color in people with COPD. The cough is usually worse early in the morning, during exercise. Smoking can worsen this symptom in the patients. Cough is accompanied by various other symptoms in the early to middle stages of the disease.