Complications resulting from sinusitis are relatively rare. However, when complications occur, they may be life-threatening and often require extensive medical or surgical treatment.

The complications of sinusitis usually involve the spread of the infection beyond the sinuses.

• The facial bones can become infected (osteomyelitis), or the lining of the brain can become infected (meningitis).
• The infection can spread outside the sinus and create a pocket of pus (abscess) in an eye socket, the brain, or facial tissue.

Sinusitis may also increase symptoms of asthma and other lifelong (chronic) lung diseases. Sinus infections are a common problem for people who have asthma. Treating sinusitis may also help control the symptoms of asthma.