Runny nose is a relatively common clinical symptom, mainly due to various irritations of the nasal mucosa resulting in congestion and edema, when the secretions also increase. This symptom is commonly caused by acute rhinitis, allergic rhinitis, nasal polyps, and when there is a cold, this symptom is also more common. Exposure to irritating gases can also stimulate the local mucous membrane and cause nasal discharge, which needs to be correctly diagnosed based on other accompanying symptoms and tests. If it is caused by allergic rhinitis, you need to take oral anti-allergic drugs such as loratadine and paracetamol, and you also need to clear the runny nose in time. In general, you need to avoid eating irritating and allergy-prone things, and you also need to avoid contact with pollen and irritating gases as much as possible, so as to prevent the recurrence of symptoms.