Uncontrolled airway inflammation contributes to persistent asthma symptoms and risks of exacerbations and airway remodelling. many asthma patients are non-adherent to inhaled corticosteroid (ICS) treatment and have a discordance between subjective symptom perception versus actual control of asthma, i.e. airway inflammation. Objective measurements of airway inflammation, e.g. fENO and sputum cell count quantification can aid clinical management. Nonetheless, there are many limitations in the tests’ availability and interpretation. Hence, these tests are used mainly for difficult-to-treat or severe airway diseases. In the 2019 Global Initiative for Asthma (GINA) strategy report, short-acting beta-agonist (SABA) monotherapy is no longer recommended in Step 1 and ICS is recommended across all asthma severity to emphasize the importance of controlling airway inflammation. Doctors should discuss and recommend the most appropriate ICS therapy (dosing regimen and inhaler device) that is acceptable to the patient, to promote adherence. Appropriate use of ICS is crucial in achieving the management targets of asthma: maintenance symptom control and prevention of asthma risks.