The earliest sign of COPD for most people is a chronic cough, according to Healthline. A cough is chronic if it persists for three months or longer out of any one year for two years.
In some cases, a person's cough may persist every day, even though there are no signs of another illness, such as a flu or a cold, states Healthline. The cough associated with COPD is usually worse in the mornings, and the mucus produced is often clear, though it can take on a yellow color. Additionally, a person with COPD may cough more after smoking or exercise.
Along with a chronic cough, many people with early signs of COPD produce a lot of mucus or phlegm, states Healthline. The lungs produce an excess amount of mucus or phlegm in people with early-stage COPD to keep out irritants and allergens, which can sometimes be up to three times the amount produced in otherwise healthy individuals. Shortness of breath is another common symptom of early-stage COPD, though it usually happens after the disease has progressed somewhat. People at this stage of the disease may experience the sensation of breathlessness when the lungs detect that it requires extra work to move air. Initially, shortness of breath may occur after exercise, but it may appear after no exertion in later stages of the disease.