The Facts
The sinuses are hollow spaces in the bones behind the face. Directly behind the nose is a cavity. On either side of the nasal cavity are large sinuses. A row of very small sinuses runs behind the bridge of the nose, and two more large sinuses are located above and behind the inner part of the eyebrows.
Sinusitis is inflammation of the sinuses. It may be associated with both bacterial and viral infections, but it may be due to non-infectious inflammation in the sinuses as well. Sinusitis can be acute and last less than 12 weeks, or chronic and last 12 weeks or more. Acute sinusitis is very common, affecting about 1 in 10 persons each year.
People with diabetes or cystic fibrosis and people who are immunocompromised are at increased risk for sinusitis, as are those who have had their nose broken previously and those who were born with a malformed septum (the dividing wall between the nostrils).