Your most likely looking at some form of COPD, or Chronic Obstructive Pulmonary Disease. COPD is usually a common chronic illness that results smoking after a while due to mucus produced to keep smoke, a foreign substandard out of the aveoli, this then becomes a more serious problem when the body expands the aveoli to allow a greater surface are but instead increases the dead space. COPD is common in elderly who smoke.
COPD come in two forms, Emphysema which is a dry COPD, and Chronic Bronchitis which is wet and usually leaves a patient bedridden much of the time.
Judging by the description I'd say COPD or Chronic Bronchitis.