Re: sinus infection
Well you can alleviate some of the symptoms but a true infection I think needs medical attention.
I've had sinus infections since I was a kid and with the exception of a few times, I've had to take a course of antibiotics to take care of it.
Some things you can do at home: flush your nostrils with saline drops, drink ginger/honey teas, inhalations with eucaplyptus oil, drink lots of fluids, cover your mouth and nose when going out in the cold air.