Sinus infections or sinusitis is an inflammation of the sinuses and nasal passages. Sinus infection can cause pressure in the eyes, nose, cheek area, on the side of the head or headache. A person with a sinus infection may also have a cough, fever, nasal congestion, thick nasal secretions and bad breath.
Sinusitis can be acute (sudden onset), or chronic (long term, the most common type).
The human skull contains 4 major pairs of hollow air-filled sacks called sinuses. Sinuses help insulate the skull, reduce its weight, and allow the voice to resonate within it.
Acute sinusitis usually lasts less than 8 weeks or occurs more than 3 times per year with each episode lasing no longer than 10 days.
Chronic sinusitis lasts longer than 8 weeks or occurs more than 4 times per year with symptoms lasting more than 20 days