This document provides an overview of pulmonary aspergillosis, caused by inhalation of the fungus Aspergillus. It discusses the main types including aspergilloma (fungal ball in a pre-existing lung cavity), allergic bronchopulmonary aspergillosis (ABPA, an immune response in people with asthma or cystic fibrosis), and invasive aspergillosis which occurs in immunocompromised people. The pathology, risk factors, clinical features, diagnosis and treatment are described for each type. ABPA is characterized by severe asthma attacks, mucus plugs and bronchial obstruction visible on chest imaging.