If an individual exhibits a dull and saddened appearance ,with a slight swelling in certain portions of the face, it might be a case of sinusitis. Though it is a widely prevalent condition, most affected individuals are not even aware that they are actually suffering from it. Sinusitis happens due to the inflammation of the mucosa located in the sinuses, which are hollow, air filled cavities in the bones of the head and face. Their major function is to heat and moisturize the air that is taken up by breathing.Sinusitis arises due to the inflammation of the bony spaces in the face. Depending on the area in the face affected, it is classified as maxillary( cheek ), erythmoidal ( between eyes ), frontal( above eyes) and sphenoid( top of the head) sinusitis. The inflammation is caused due to the allergy, bacterial and viral infection, and even autoimmunity.