Migraine
      Headache is a common symptom of Sinusitis and “Sinus Headache” rarely but can be a misdiagnose, of a Migraine. This confusion occurs in part because Migraine involves activation of the Trigemnal which innervate both the sinus region but also the meninges which surround the brain. As a result, direct determination of the site of pain origination can be confused on a cortical level. Additionally, nasal congestion is not an uncommon result of migraine headaches, further confusing the issue. Most patients with sinusitis have some sort of facial pain, pressure, or headache, not all patients who attribute the symptom of headache to their sinuses may have legitimate diseases of the sinus. Acute and chronic sinusitis can cause pressure within the sinus cavities of the head, but this is associated with pain on palpation of the sinus area.

Allergic Rhinitis
      Allergic rhinitis is an IgE mediated immunologic response of nasal mucosa to air-borne allergens and is characterized by watery nasal discharge, nasal obstruction, sneezing and itching in nose. It may lead to recurrent sinusitis because of obstruction to sinus ostia.

Deviated Nasal Septum

      Nasal secretions with a very high eosinophil count associated with Allergic rhinitis may appear yellow or green and the patient may be diagnosed as having infective rhinosinusitis. Allergy leads to swelling and inflammation of nasal mucus membranes causing mechanical obstruction, which impedes drainage and clearance from the sinuses and allows secondary bacterial infection.

Deviated Nasal Septum
      Deviated nasal septum may obstruct the sinus ostia resulting in poor ventilation of the sinuses. Therefore it forms an important cause to predispose or perpetuate sinus infection.

Nasal Polyp
      Nasal polyps are nonspecific oedematous masses usually eosinophilic formed as sino nasal response to variety of inflammatory causes that are usually not infectious. Polyps are seen in chronic rhinosinusitis of both allergic and non-allergic origin. Non Allergic Rhinitis with Eosinophilia syndrome (NARES) is a form of chronic rhinitis associated with polyp. These may obstruct the sinus ostia and in turn lead to secondary bacterial infection.