Sinusitis can be prevented by lessening your interaction with people with colds. You should also steer clear of upper respiratory viruses and infections, and be sure to wash your hands often using soap and water, particularly before having a meal. Because allergies can cause sinusitis, it is important that you consult with your doctor regularly to manage your allergy symptoms. Avoiding pollutants and cigarette smoke that can cause the lungs and nasal passages to swell is also important. If your home has dry air, a clean, mold-free humidifier will add humidity to the atmosphere in your home, which also helps to prevent sinusitis from developing.