Controlling common allergens can help some people diminish sinus pressure and congestion. For people with allergies, allergens like dust, mold, pet dander, and pollen can all lead to sinus problems, says Kelleher. You can cut back on allergy-related sinus problems by using an air conditioner in your house and your car during warm weather and keeping windows closed during pollen season. Make sure pets stay out of your bedroom and cover your mattress and pillows in plastic to prevent exposure to dander and dust mites. In addition, wear a mask if you are working in moist areas to protect against mold.