The person may have an insidious course with increased respiratory rate, foul-smelling sputum, hemoptysis, and fever. Complications may occur, such as exudative pleural effusion, empyema, and lung abscesses. If left untreated,<unk>  can progress to form a lung abscess. Another possible complication is an empyema, in which pus collects inside the lungs. If continual<unk>  occurs, the chronic inflammation can cause compensatory thickening of the insides of the lungs, resulting in bronchiectasis.
Aspiration pneumonia
Chemical pneumonitis
Bacterial pneumonia
Tuberculosis
Viral pneumonia
Pulmonary aspiration
Occult pneumonia
Pleural empyema