Without being ill, the patient starts to cough suddenly, and it lasts for a while. Sooner or later, the patients become too annoyed and turn to the doctor just to find out they are having a chronic obstructive pulmonary disease (COPD). The patient does not have a fever. However, he has all other features typical for flu or cold. As a rule, the coughing manner is wet even though it can be dry too. The mucus is either yellow or regular, but thicker.