Eight months baby runny nose can be acute upper respiratory tract infection, sinusitis and other causes, you can take general treatment, erythromycin and other medications. 1. Acute upper respiratory tract infection: can be manifested as runny nose, sneezing, coughing and other manifestations. Can be under the guidance of a doctor to be sea saline nasal spray, dilute nasal secretions, promote the discharge of secretions, relieve nasal congestion symptoms. 2. Sinusitis: often due to repeated respiratory infections and nasal ventilation and drainage caused by poor, can be manifested as yellow-green nasal discharge. Can strengthen the local cleanup, in addition to sea salt water spray nasal cavity, if necessary, can follow the medical advice to be erythromycin and other anti-infective treatment. Eight months baby runny nose may also be allergic rhinitis and other diseases, it is recommended to go to the hospital in a timely manner to improve the blood allergen test, give targeted treatment or treatment, the above drugs should be used under the guidance of the doctor, do not take medication.