A Clinician's Guide to AsthmaAbout This Hardback Asthma is a chronic inflammatory condition that affects the airways of the lungs. In asthma, airway hyper responsiveness leads to recurring episodes of breathlessness, chest tightness, wheezing and coughing. There is no precise way to diagnose asthma. It is usually suspected on review of symptoms, whether these occur or worsen with exercise, or on exposure to allergens, viral infections or air pollution. Spirometry can be used to