Can sinusitis cause back of neck pain, etc?

I had the flu one week, the second week seemed to be progressing fine, then the third week got a headache then starting feeling really bad. My nose does not run but it feels like I can point to a place deep inside my head, behind my eye that feels tight and uncomfortable.  The back of my neck, more so on that particular side gets sore to turn and even runs up my head, even feels sore to the touch.  During the first week I felt dizzy, a little nauseous, and what I describe as a spaced out feeling in my head and eyes, felt terrible. I am a little improved now. It's been 2 weeks of this. I am wondering if this could be from sinuses or I have picked up another kind of virus. Thanks.

[National Jewish]

It is possible that this is a virus, but more likely that you have developed a secondary sinus infection. This is quite common following a viral respiratory infection. With the symptoms you are describing, I would suggest that you see your doctor. Antibiotics are the best way to treat a sinus infection.