Yellow-green nasal mucus is mostly caused by bacterial infection, and the components include necrotic mucosal cells, bacterial necrosis products engulfed by macrophages, and nasal mucosal secretions. Acute sinusitis, nasal polyps, colds, etc. can appear yellow-green nasal discharge. 1, acute sinusitis: acute sinusitis is due to low body immunity and resistance, bacterial invasion of sinus mucosa, resulting in sinus mucosa congestion, edema, exudation and hyperplasia, patients will appear facial swelling, headache, fever, nasal congestion, while the nasal cavity will flow yellow-green secretions. If sinusitis is identified, symptomatic anti-inflammatory treatment and oral antibiotics are needed, as well as repeated rinsing of the nasal cavity with saline to flush out the secretions and relieve nasal congestion. Patients also need a light diet, quit smoking, quit drinking; 2, nasal polyps: nasal polyp infection can be accompanied by runny nose, unilateral or bilateral nasal flow yellow-green watery discharge, most patients with nasal polyps need further surgery; 3, cold: it is recommended to go to the hospital to do routine blood tests to clarify the infection, you can take antibiotic drugs to control the infection. In addition, the color of nasal discharge will also change when you get cold or fire. When cold, the nasal mucosa is stimulated, so that the secretion increases. If you don’t clear it in time, the nasal cavity may be blocked. You should pay more attention to the change of temperature on weekdays and add or remove clothes in time to avoid getting cold or getting fire.