There are many tests for the lungs, and often a chest X-ray or chest CT is needed to detect tumors, inflammation, bronchiectasis or chronic bronchitis in the lungs, especially to rule out coughing, coughing or wasting or fever caused by tumors. Lung tests are likely to be symptomatic of infection and require hematological tests, such as routine blood tests, C-reactive protein, and antibodies to Mycoplasma pneumoniae, which are also necessary. If a dry cough occurs with no obvious symptoms in the lungs, it may also be caused by asthma or cough variant asthma, and it is necessary to further check bronchodilator test or bronchial excitation test to confirm whether there is any airway hyperreactivity, which is also necessary. In the presence of lung disease, it is sometimes necessary to check respiratory function, such as the occurrence of ventilation disorders, and respiratory function tests are also necessary.