Brief Answer:
Slight Rise,
Sinusitis can raise it.
Detailed Answer:
Dear XXXXXXX
ESR is a non-specific marker. It can be increased in any infection or inflammation; so it is co-related clinically with other signs and symptoms , as well as with other investigations.
ESR Of 30 mm/hr is not very high, and since you have been diagnosed with sinusitis, then yes, this much ESR rise is possible in sinusitis.
You take your proper treatment for sinusitis, and after a few weeks when your doctor says that you are cured, you can get it repeated. If it settles, nothing to worry. If it doesn't , you may require further investigations.
At present, with the currently available history and report, I can assure you that there is nothing that much wrong for you to be worried regarding slightly raised ESR.
If you have any other problem like
joint pains, Reddening of eyes frequently, oral ulcers, or any other medical history, do tell us.
I hope I have answered your query. Still if you have any doubts, you can ask me.
Stay Healthy