My girlfriend is getting sick often, like once a month or so. It is usually a cold/flu thing or most often a sinus thing (whether it's an infection or not). To make matters worse, anytime she gets sick her voice gets weak (or goes away completely). You can imagine how this effects ones job.

Her bedroom is in the basement (it's finished off) and there is always a dehumidifier on down there. Since she never had voice problems or sinus problems before moving into this house 3 years ago, I was wondering if the basement and/or dehumidifier could be attributing to any of this in any way?

P.S. 18 months ago she had her tonsils removed and 6 months ago had a deviated septum fixed