Inflammation of the sinuses. Acute sinusitis, usually due to infections such as the common cold, causes localized pain and tenderness, nasal obstruction and discharge, and malaise. Nose drops or inhalations containing drugs that contract blood vessels help drain the sinuses. Antibiotics may be used for bacterial infections. Chronic sinusitis, with frequent colds, pus, obstructed breathing, loss of sense of smell, and sometimes headache, may follow repeated or untreated acute attacks, particularly with impaired breathing or drainage. If antibiotic therapy or repeated lavage (rinsing out) does not help, surgery to open passages for drainage may be needed.