Induced sputum: current progress and prospect.

Induced sputum is a noninvasive, safe, cost-effective, and reproducible method that is particularly advantageous for individuals who do not naturally produce sputum or provide inadequate samples. Its higher quality than spontaneously produced sputum makes it valuable in various respiratory conditions such as chronic obstructive pulmonary disease, asthma, lung cancer, and infectious respiratory diseases. Despite its potential, the clinical use of induced sputum is limited. In conditions like interstitial lung disease, where patients often have a dry cough, induced sputum shows promise, albeit with limited research. This review emphasizes the usefulness of induced sputum in such conditions, aiming for induced sputum to be established as a routine supplementary examination in clinical settings.