Children with yellow nasal discharge may be caused by upper respiratory tract infection, sinusitis, nasal polyps and other reasons. 1. Respiratory tract infections: the body’s resistance to decline vulnerable to pathogen invasion and triggered by upper respiratory tract infections, upper respiratory tract infections is the nose, pharynx, throat and other infections of bacteria or viruses, the nasal mucosa inflammatory reaction, may flow yellow snot. 2. Sinusitis: sinusitis is generally caused by bacterial infection, a limited inflammatory disease, inflammation stimulation will have the performance of yellow nasal discharge. 3. Nasal polyps: children with nasal polyps growing in the nasal cavity, affecting the discharge of secretions in the sinuses, resulting in rhinitis attacks, there will also be symptoms of yellow nasal discharge. Children with yellow nasal discharge may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.