Bronchial asthma is a chronic inflammatory airway disease. Patients primarily exhibit symptoms of episodic wheezing, shortness of breath, chest tightness, and coughing, which usually can be relieved with or without medication. Typically, during an attack, there is wheezing and audible stridor. A diagnosis can usually be made based on symptoms and medical history, as well as physical examination. However, for atypical patients, further tests may be necessary. Generally, the main tests for asthma patients are pulmonary function tests, which include provocation tests and relaxation tests, as well as the 24-hour peak expiratory flow variability. These tests are helpful for the definitive diagnosis of bronchial asthma.