Summary Clinical features of asthma such as dyspnoea, chest tightness and wheezing can mimic other respiratory conditions. It is important to take a careful history and examination and ideally demonstrate reversible airflow obstruction. Other clinical features of asthma arise during periods of bronchoconstriction (ie. exercise, smoking, stress, cold air). Exacerbation of asthma confounds the breathing difficulty, cough and wheeze in patients.