8 months baby runny nose is mostly seen in normal physiological phenomenon, respiratory tract infection, intervention needs to be specifically analyzed, such as indoor temperature should not be caused by the need to regulate the indoor temperature, respiratory tract infections can be appropriate to apply the physiological sea saline nasal spray. 1. Normal physiological phenomenon: 8-month-old babies are young, the nasal cavity is narrower, the nasal mucosa is easy to be affected by external factors, such as edema, when the external environmental temperature or indoor temperature is low, there can be symptoms of runny nose, we need to pay attention to warmth, wear a mask, as appropriate, and appropriately regulate the indoor temperature, to avoid stimulation of such factors, and can be relieved on their own. 2. Respiratory infections: such as acute upper respiratory tract infection, mostly caused by viral infections, can be manifested as runny nose and other local symptoms, accompanied by fever, runny nose symptoms are self-limiting, often in 3-7 days can be relieved on their own, during the period of time in the physician’s guidance, the use of physiological saline local nasal spray, negative pressure to attract intranasal secretions and other treatments. If the baby frequent runny nose or accompanied by other uncomfortable symptoms, it is recommended to consult a doctor in a timely manner in order to clarify the cause of the disease, the specialist physician for treatment, do not self-medication.