<p>Corticosteroids have broad anti-inflammatory effects to treat asthma and COPD. They do not alter the disease’s progression, but they do improve the function of lung, symptoms, and quality of life. Additionally, they also reduce the exacerbation of both disorders. In asthma, they reduce mortality, but not in COPD. After penetrating the cytoplasm of the cell, the corticosteroid binds to an inactive glucocorticoid receptor complex. Thus, the activated glucocorticoid receptor attaches to DNA at the glucocorticoid response element sequence, promoting the development of anti-inflammatory proteins (transactivation) and suppressing the transcription and secretion of various proinflammatory cytokines (transrepression). The available corticosteroids differ regarding their therapeutic index and potency. All age groups utilize corticosteroids, but because younger and smaller children can get larger mg/kg doses of corticosteroids than older children, they may be more susceptible to adverse systemic effects. Corticosteroids are most beneficial when taken at low to medium doses. While greater doses may help certain patients, there is little additional improvement shown with them. The benefits of corticosteroids for COPD are more debatable, even though they are the recommended treatment for chronic asthma in people of all ages. When taken as instructed, at low to medium dosages, ICS adverse effects are rare however, the risk increases with greater dosages. Even though many kinds of novel treatments have been invented and analyzed, it is unclear that any of them will take the position of ICSs as the first, long-term controller medication for asthma. However, a better initial control treatment for COPD might be established. This chapter focuses on the role, mechanisms, including glucocorticoid receptor binding and modulation of pro-inflammatory gene expression, steroid resistance, clinical applications, challenges, and limitations of corticosteroids in the management of asthma and COPD.</p> Graphical abstract <p></p>