4 months baby has been running nose, may and allergic rhinitis, upper respiratory tract infections and other factors related to the need to clarify the cause of targeted treatment, the treatment is mainly based on drugs. 1. Allergic rhinitis: If the baby has a runny nose, and the body does not have a fever and other adverse reactions, may be related to allergic rhinitis, you can follow the doctor’s instructions for allergen screening, life to reduce exposure to allergens. If the symptoms are not relieved for a long time or even aggravated, you can consult the doctor in time for anti-allergy treatment. 2. Upper respiratory tract infection: If the baby has a bacterial or viral infection caused by upper respiratory tract infection, may also appear to have been the situation of the runny nose, the need for timely diagnosis to clarify the type of pathogens, and targeted anti-infective treatment, bacterial infections require the use of sensitive antibiotics, such as cephalexin, etc., viral infections are generally supportive of the treatment. In addition, the 4-month-old baby nose has been flowing also need to be alert to cerebrospinal fluid leakage and other possibilities. It is recommended to consult a doctor for a clear diagnosis and targeted treatment. The above drugs need to be taken under the guidance of a doctor, not self-medication.