what does the last word you said for 'signs' mean?
It is mucus that is coughed up from the lower airways (the trachea and bronchi).
Sputum
Sputum is mucus that is coughed up from the lower airways (the trachea and bronchi). 
what is the full form of c o p d Chronic obstructive pulmonary disease what are its signs? Shortness of breath, and a cough that produces sputum. tell me more about the effects of the 1st one In severe COPD, vigorous coughing may lead to rib fractures or to a brief loss of consciousness.
wiki:11650960
Sputum [SEP] Introduction
Sputum is mucus that is coughed up from the lower airways (the trachea and bronchi). In medicine, sputum samples are usually used for naked eye exam, microbiological investigations of respiratory infections and cytological investigations of respiratory systems. It is critical that the patient not give a specimen that includes any mucoid material from the interior of the nose. Naked eye exam of sputum can be done at home by a patient in order to note the various colors (see below). Any hint of yellow color (pus) suggests an airway infection (but does not indicate the type of organism causing it).