Level 1: Causes of baby\’s nasal congestion There are many reasons for baby\’s nasal congestion, which may be colds, allergies, air pollution, etc. Colds are the most common cause, and viral infections can cause swelling of the mucous membranes in the nasal cavity and an increase in secretions, leading to nasal congestion. Allergies are also a common cause. Allergic rhinitis causes an inflammatory reaction in the nasal cavity, leading to nasal congestion. In addition, air pollution can also irritate the baby\’s respiratory mucosa and cause nasal congestion. Level 2: How to relieve your baby’s nasal congestion 1. Nasal wash with warm water: Pour warm water into a small cup and let your baby