It is extremely common and can cause considerable discomfort and pain. It may also be caused by other infections such as fungal infections.
Many people suffer from acute sinusitis after they catch a common cold.
Once a person develops a tendency to get sinusitis, it may recur every time the person catches another cold. The sinuses have a membranous lining which continually produces mucus that drains into openings in the middle and at the back of the nasal cavity through narrow channels. There are two frontal sinuses just above the eyebrows, two maxillary sinuses by the cheekbones, two ethmoidal sinuses between the nasal cavity and the eye sockets. These drain into the middle of the nose. The sphenoidal sinuses, a group in the bones that form part of the base of the skull, drain into the back of the nose.