Production of sputum on coughing with a feeling of chest heaviness is indicative of lower airway infection. You shoudl meet a doctor for a course of antibiotic. This goes for 7 to 10 days along with some symptomatic medication to loosen the mucus and dilate the airways.
it is common to have lung infection
once in a while even for a healthy 45 yr old female. Practice spitting out the sputum whne you have discomfort breathing.