We at MedyBlog want to provide you with reliable medical blogs from top doctors. We believe accurate medical information available at the right time can save and change lives.Each sinus has an opening for the in and out of the air. The issue is that dust, virus, bacteria, fungus, and atmospheric air will enter and settle in the sinuses. To remove these settlements, the skin lining in the sinus keeps secreting fluid that comes out from the nose and goes into the throat. This fluid cleans our sinuses by flushing out unwanted particles. Fluid stagnation can occur if the sinus opening through which fluid flows is smaller than it should be. Viruses, bacteria, and fungi can grow in this stagnant water, causing sinusitis (infection and inflammation of the sinuses).