Untreated sinusitis can lead to persistent nasal congestion, runny nose, headache, impaired sense of smell and other symptoms, as well as respiratory diseases and other complications. 1. Non-relief of sinusitis symptoms: If sinusitis is not treated, it will lead to worsening of nasal symptoms, prolonged airlessness, runny nose, headache and decreased sense of smell. 2. Respiratory function: if left untreated for a long time, nasal secretions backflow into the throat for a long time may induce respiratory system infections and respiratory system related diseases. 3. Other complications: It may also involve the orbit, leading to the emergence of orbital complications, such as orbital cellulitis, and involve the skull may appear intracranial complications, such as purulent meningitis. If the secretion enters the Eustachian tube and enters the tympanic cavity, the patient is prone to develop secretory otitis media or even purulent otitis media. Therefore, if the patient suffers from sinusitis, it is recommended to go to the hospital for treatment in time to avoid delaying the condition.