The dangers of sinusitis include its impact on normal life such as nasal congestion, and complications such as smell disorders can also occur. 1. Symptoms (1) Local symptoms: Sinusitis may cause nasal congestion, runny nose, headache or local pain in the cheeks. (2) Systemic symptoms: acute sinusitis is often secondary to upper respiratory tract infections or acute rhinitis, and may be accompanied by symptoms such as chills, fever, loss of appetite, and malaise; chronic sinusitis may also be accompanied by symptoms such as coughing and fatigue. 2.Complications (1) Impairment of sense of smell: patients with sinusitis may have conductive olfactory loss due to nasal congestion, and the sense of smell can be restored after the nasal congestion improves. However, some patients may have sensory hyposmia, which often remains as permanent hyposmia. (2) Others: Commonly include pharyngitis, tonsillitis, periorbital cellulitis, meningitis and so on. If there is any discomfort, it is recommended to consult a doctor in time for diagnosis and treatment.