Main causes of sinusitis
Common Cold: The most common cause is a viral cold. This causes swelling in the sinuses.
Allergies: Allergies to dust, pollen, smoke, perfumes or certain foods can cause swelling in the sinuses (Allergic Rhinitis).
Bacterial Infection: When a cold lasts a long time, it turns into a bacterial infection and pus forms in the sinuses.
Structural Changes in the Nasal Cavity: Deviated Nasal Septum or Nasal Polyps can obstruct the airflow in the sinuses and cause swelling.
Smoking: Smoking impairs the function of the sinuses and increases the risk of infection.
Dental problems: Infections in the upper teeth can sometimes spread to the sinuses.
