Patients with asthma experience exacerbations due to the airflow obstruction caused by the narrowing of lung passages. The exacerbations vary between simple and lifethreatening, which is unpredictable. As a result, visits to the emergency department and hospitalization incur an enormous health care expenditure. Prediction on the severity of exacerbations is primarily vital to decide on the further course of treatment where conventional tests like spirometry provide mechanical aspects of the lung pathway obstruction. The advent of imaging modalities provides an advanced notion of the severity. Hence, in this review, the epidemiology of asthma, a diagnostic procedure using the different radiological techniques, various factors leading to lung pathway obstruction, and suitable medicines were discussed.