The baby has clear runny nose for 20 days, if the baby does not have thick nasal discharge, it means there is no serious infection, but only the nasal discharge has increased, this situation may be related to upper respiratory tract infection or allergic rhinitis, it is necessary to distinguish the cause according to the specific performance and target the treatment. If the baby has a runny nose after catching a cold, it may be a common cold caused by upper respiratory tract infection, and the condition is mild, so only a runny nose and no other symptoms appear. Generally, the cold is self-limiting and can heal itself in about 7 days, but when the baby is not in good health, or recently the baby is not resting well, eating less, etc., the recovery may be slower and the nose is still running for 20 days. You can take some anti-inflammatory drugs under the guidance of the doctor to help your baby heal. After the upper respiratory tract infection is controlled, the runny nose will also be relieved until it disappears. If the baby has clear runny nose at the change of season, especially in spring or after late autumn and winter, it may be allergic rhinitis caused by pollen or cold air, which may keep running clear nose for 20 days because the allergen continues to stimulate the nasal mucosa. In allergic rhinitis, the baby may also have nasal pain, forehead pain and fever. You can go to the hospital in time to clarify what the allergen is and avoid contact in daily life, and the symptoms will usually be relieved, or you can use anti-allergy drugs carefully under the guidance of the doctor. Regardless of the reason, when a baby’s runny nose lasts as long as 20 days, he or she should promptly go to the hospital to check the situation. If your baby also has fever, clear nose turning to thick nose, headache, red throat and cough, you should pay more attention to seek medical attention in time. During the treatment period, it is not recommended to stuff the baby’s nostrils with cotton swabs or paper, nor is it recommended to wipe the baby’s nose with force, but to gently wipe the baby’s nose with facial tissue or wet wipes, or use saline to clean the baby’s nasal cavity, but be careful to avoid choking the baby. When cooling down or entering an air-conditioned room in summer, pay attention to adding clothes to your baby to avoid catching cold.