It is possible to use saline alone for nebulization, but whether to use saline alone needs to be judged according to the specific disease and symptoms. Saline nebulization alone can play a role in moisturizing the airway, improving ventilation, helping to remove dust and infected material from the nasal cavity, reducing discomfort in the nasal cavity, can improve dryness-induced discomfort in the mouth and nose, mild coughing and other symptoms, but also dilute phlegm, help phlegm discharge and so on. Nebulization therapy generally uses saline and other diluents plus medication, and is commonly used in clinical practice for diseases such as obstructive airway diseases, upper respiratory tract infections and lung infections. Depending on the disease, commonly used nebulized drugs include theophylline, anticholinergics, β2 agonists, leukotriene receptor antagonists and hormonal drugs. Saline alone should not be used when any of these diseases are present. It should be noted that nebulization therapy should be carried out under the guidance of a physician and in strict accordance with medical advice, and should not be implemented on its own.