Most colds and runny noses in 4 year old babies are caused by weather changes, low immunity of babies and viral and bacterial infections. After the cold should be given standardized care and medication. 1. The baby has a blocked nose and runny nose, can with physiological sea salt water spray nose, drink more hot water, pay attention to rest, pay attention to warmth. 2. medication can be taken orally under the guidance of the physician pediatric cold granules and other medication. 3. But if there is obvious fever and other symptoms, combined with bacterial infection, you can follow the doctor’s instructions to use anti-infective drugs, such as cefixime and so on. Pediatric runny nose may also have other causes, it is recommended to consult a doctor in a timely manner, after a clear diagnosis of targeted treatment.