Sinusitis can be caused by various factors, but they are commonly caused by:

Anatomical abnormalities of the nose -  crooked nasal septum, untreated allergic rhinitis (allergic inflammation of airways in the nose), and tooth infections.

Fungal infections – usually affects people with a weakened immune system.

Viral and bacterial infections –  can be resolved with the right treatment in a reasonable amount of time.

The typical signs and symptoms of a Sinusitis infection are:

Bad breath

Coughing caused by mucus dripping down the back of the throat

Difficulty breathing through the nose due to nasal congestion

Fatigue

Feeling full in the face

Feeling heavy in the head

Fever

Nausea and dizziness

Pain and swelling around the eyes, nose, cheeks and forehead

Reduced sense of smell and taste

Thick yellow- or green-coloured nasal discharge

Treatment for Sinusitis is usually quick and easy. Most of the time, antibiotics and decongestants will help manage an infection and allow the natural flow of mucous to be restored in more common cases. Treatment of chronic cases might require surgical intervention in order to reverse any obstructions in the sinuses. Surgical options include:

Balloon Sinuplasty - less invasive than FESS, it uses specialised instruments to insert a balloon to dilate the sinus opening and therefore restore normal mucus flow in the sinuses, without tissue or bone removal

Functional Endoscopic Sinus Surgery (FESS) - a minimally invasive procedure that consists of inserting an endoscope through the nose to clear out infected tissues in the nose