Runny nose is caused by the virus invading the nasal mucosa, which becomes congested and edematous, and nasal secretions increase, so the nose will run when you have a cold. Cold and runny nose is also a manifestation of the immune system, the nasal cavity secretes mucus to prevent the re-invasion of other pathogenic microorganisms; if the symptoms of nasal congestion and runny nose are serious, you need to take drugs to improve the runny nose and nasal congestion, such as compound aminophenol alkylamine granules and so on. Cold and runny nose should not eat cold food, especially iced drinks, ice cream; spicy food should not be eaten, such as chili peppers, etc., and avoid drinking strong tea; pay attention to cold to avoid catching a cold, try not to eat barbecue, hot pot and other stimulating food. If the symptoms of cold and runny nose are serious, or if the symptoms persist and do not get better after taking medication, the patient should go to the hospital in time for treatment.