The change of pus nasal discharge into clear nasal discharge represents that the nasal disease is in the recovery period and is a sign of improvement. When patients suffer from cold, upper respiratory tract infection, sinusitis and acute rhinitis, purulent nasal secretions will increase and pus nasal discharge is more common, along with nasal odor, nasal congestion, headache and other manifestations. After active anti-inflammatory treatment and nasal irrigation, the purulent nasal discharge will gradually decrease and change from purulent nasal discharge to clear nasal discharge. Because after the nasal mucosa is stimulated by inflammation, the state of nasal mucosa belongs to recovery period, the nasal cavity will gradually change from purulent to clear to disappear, and there will be corresponding changes in nasal discharge. Therefore, purulent nasal mucus becomes clear nasal mucus is a manifestation of nasal inflammation recovery period, and it is not a pathological state.