Pulmonologists are medical doctors (usually internal medicine physicians) who specialize in the diagnosis and treatment of pulmonary conditions and diseases, such as asthma, chronic obstructive pulmonary disease (COPD), emphysema and pneumonia.

Pulmonologists will test the breathing performance of a patient with various tests, and may diagnose breathing problems with the use of a bronchoscopy procedure. This is a diagnostic procedure in which the pulmonologist inserts a thin, flexible tube (with a very small camera on the end) into the trachea and bronchi to take samples of suspicious areas of the lung.