A common abnormal physical finding is wheezing on auscultation, which confirms airflow limitation. The upper respiratory tract and skin should also be examined for atopic conditions such as rhinitis or dermatitis. Lungs function test is another diagnostic tool that access the function of the lungs, the two most common lung function tests used to diagnose asthma are spirometer and methacholine challenge test. Spirometer is simply a breathing test that measures how much and how fast you can blow air out of your lungs. According to Kaplan AG, “Spirometer measures the forced vital capacity (FVC, the maximum volume of the air that can be exhaled) and the force expiratory volume in one second (FEV1)” (CMAJ 2009). Thus, from a personal experience, a diagnosis of asthma is confirmed when there is an improvement in the forced expiratory volume 1 of at least 12% and at least 150 ml 20 minutes of administration of an inhaled rapid-acting bronchodilator. In a general population standard, the ratio is usually greater 0.8, therefore anything less will be considered airflow limitation and also support the diagnosis of