What Causes Frequent Sinus Infections?

Chronic sinus infections are one of the most common illnesses found around the world. Millions of people are diagnosed each year and many of those people suffer from frequent sinus infections.  Sinus infections leave you feeling like an elephant is standing on your face and can come with a variety of unpleasant symptoms. But what is chronic sinusitis? What causes it and what can you do to preven...