Sinusitis. medically known as rhinosinusitis, a sinus infection occurs when your nasal cavities become infected, swollen, and inflamed. sinusitis is usually caused by a virus and often persists. Feb 10, 2021 · sinusitis or sinus infection is inflammation of the air cavities within the passages of the nose. sinusitis can be caused by infection, allergies, and chemical or particulate irritation of the sinuses. most people do not spread sinus infections to other people. Take these steps to help reduce your risk of getting acute sinusitis: 1. avoid upper respiratory infections. try to stay away from people who have colds. wash your hands frequently with soap and water, especially before your meals. dua. manage your allergies. work with your doctor to keep symptoms under control. 3. avoid cigarette smoke and polluted air. tobacco smoke and other pollutants can irritate and inflame your lungs and nasal passages. 4. use a humidifier. if the air in your home is dry, such as it is if you have f...