Allergic cough can be determined by clinical symptoms, reversible airway obstruction, airway hyperresponsiveness testing, and allergen testing. 1. Clinical symptoms: Allergic cough is mainly caused by exposure to allergens. Clinical symptoms such as cough and shortness of breath are often present. 2. Reversible airway obstruction: Reversible airway obstruction is mainly detected by bronchodilator test and peak expiratory flow rate variability. If the test is conducted continuously for two weeks, and the peak flow rate variability >20% three times a week, it can be judged as positive. 3. Airway hyperresponsiveness test: Airway hyperresponsiveness test, also known as bronchial provocation test, is the main means of diagnosing allergic cough. Through the use of different exciters to cause abnormal bronchial contraction, and then determine the changes in lung function indicators, in order to determine the degree of airway hyperresponsiveness. 4. Allergen testing: Allergic cough is a condition triggered by exposure to certain allergens, so testing to identify allergens can lead to early prevention and treatment. Commonly used tests include skin tests (skin scratch test, skin prick test) and serum specific IgE test. Allergic cough can be diagnosed by the presence of the above symptoms and the presence of any one of the objective tests for variable airflow limitation, except for coughs caused by other diseases. Specific tests need to be carried out in a timely manner in a hospital under the guidance of a physician, and at the same time, active treatment can be carried out to avoid delays in the condition.