Sinusitis is a nonspecific inflammation of the sinus mucosa, a common and frequently occurring illness. Its onset is often due to diseases of the nasal cavity such as nasal polyps, allergic rhinitis, deviated nasal septum, hypertrophy of the nasal turbinates, or nasal cavity tumors that block the sinus ostia, all of which can lead to sinusitis. Patients with sinusitis typically experience symptoms such as nasal congestion, purulent nasal discharge, and headaches. Usually, a diagnosis requires sinus CT scans, either plain or enhanced, to confirm the occurrence of sinusitis. Once diagnosed, most cases of sinusitis can be alleviated with oral medication. However, a small number of patients who are difficult to cure may need surgery to open the sinus ostia and maintain drainage, thus curing the sinusitis.