The causes of nasal congestion and thick yellow nasal discharge include colds, sinusitis and chronic rhinitis. 1. Colds: acute rhinitis secondary to bacterial infection, there will be symptoms of thick yellow nasal discharge, accompanied by fever, headache, depression, nasal congestion and other symptoms. 2. Sinusitis: patients with sinusitis will secrete a large amount of purulent secretion due to the inflammation and edema of the nasal mucosa, which will lead to nasal congestion and thick yellow nasal discharge, accompanied by headache and pain in the facial area, and loss of sense of smell. 3. Chronic rhinitis: when this disease has an acute attack under the action of viruses or allergies, it can lead to congestion and edema of the nasal mucosa, and the condition of clear nasal discharge, and after combining with bacterial infections, it will be manifested as the symptom of yellow nasal discharge. If the phenomenon of thick yellow nasal discharge, go to the hospital in time, clear diagnosis, and follow the doctor’s instructions for treatment.