Viral sinusitis usually starts with a cold and improves within 7 to 10 days
Bacterial sinusitis is more likely if symptoms last more than 10 days without improvement
Bacterial sinusitis is more likely if symptoms get worse after initially improving
High fever can suggest bacterial sinusitis, especially with thick nasal discharge and facial pain
Severe facial pain or pressure may point to bacterial sinusitis
Thick yellow or green mucus alone does not prove bacterial infection
Viral sinusitis often causes milder symptoms that gradually improve
Bacterial sinusitis is more likely if symptoms are one-sided and persistent
Bad breath, tooth pain, or reduced sense of smell can occur in both but may be more concerning if prolonged
A doctor may diagnose bacterial sinusitis based on symptom pattern rather than mucus color alone