Baby only runny nose, may be upper respiratory tract infection, allergic rhinitis, skull fracture, etc., can be relieved by medication, patients should follow the doctor’s instructions for treatment. 1. Upper respiratory tract infection: upper respiratory tract infection is often caused by viral and bacterial infections. In the early stage of upper respiratory tract infection, it is mostly watery or mucous, and in the later stage or combined with bacterial infection, there can be pus and snot. At the same time, accompanied by dry throat, itchy throat, sore throat and other symptoms. Clinically, it can be given sea saline nasal spray, ephedrine nasal drops to shrink the nasal mucosal blood vessels. If you consider bacterial infection or virus combined with bacterial infection, you can follow the doctor’s instructions to be amoxicillin, cefuroxime and other antibiotics anti-infection treatment. 2. Allergic rhinitis: Allergic rhinitis is an inflammation of the nasal cavity caused by contact with allergens. It is characterized by watery nasal discharge in large quantities, accompanied by sneezing and nasal itching. Patients should stay away from allergens in time, and follow the doctor’s instructions to use loratadine and other drugs for treatment. 3. Skull fracture: cerebrospinal fluid leakage caused by skull fracture may be misunderstood as runny nose, which should be repaired by surgery in time to reduce cerebrospinal fluid leakage. If you feel unwell, you should go to the hospital in time to avoid delaying your condition or causing adverse reactions.