There is no strict interval for nebulization, which is generally related to the severity of the disease, but the minimum interval should be 4~6 hours. If an acute attack of bronchial asthma is accompanied by severe cough, sputum, shortness of breath, the interval between two times can be shortened to 4-6 hours; if nebulization is used in the long-term treatment of bronchial asthma, the recommended interval between the two nebulizations is 24 hours. If nebulization is used for the treatment of upper respiratory tract infections, accompanied by mild cough, sputum symptoms, the general 1 day for 1 time nebulization. The interval between 2 nebulizations for pneumonia and bronchitis is usually 8 hours. Nebulizer treatment must be under the guidance of the doctor to adjust the medication program and interval time according to the condition.