Sinusitis occurs when the spaces inside your nose and head (sinuses) are swollen and inflamed.
Serious complications of chronic sinusitis complications may include:
1)Vision problems If your sinus infection spreads to your eye socket, it can cause reduced vision or possibly blindness that can be permanent.
2)Infections Uncommonly, people with chronic sinusitis may develop inflammation of the membranes and fluid surrounding the brain and spinal cord (meningitis)