How do I know if I have sinus problem? What are the symptoms?

Sinus problems. Sinusitis often presents with pressure/pain in sinus areas (below & between eyes, forehead), may cause referred pain to back of head, may cause pain/pressure on upper teeth. If sinus drainage passages are swollen shut, pain worsens; fever may ensue. Opening passages with decongestant may allow thick, yellow-green discharge to be blown out.