If you suffer from seasonal allergies, and your symptoms involve nasal and sinus congestion 24-7, you may want to take a look at the dairy in your diet. Dairy products like milk, cheese, yogurt, and ice cream may be making your allergy symptoms worse. Casein, the naturally occurring protein in dairy products, can promote the formation of mucus. It can also make existing mucus thicker in your nose and sinuses, leaving you completely congested. It may also cause a runny nose or the ever annoying post nasal drip.
Of course, conventional doctors may not agree with the notion that dairy promotes mucus (there's no scientific evidence, but maybe because there have been no studies - I don't know), but many people swear that ditching dairy has cured their sinus problems. So if you are curious, you'll have to test the theory yourself. Try eliminating all things dairy for at least 1 to 2 weeks and see how you feel. It's made a world of difference for me, my nose and my sinuses, so I definitely think it's worth a shot.
Here's a cool tidbit of info - casein is also used to make adhesives, like glue, beer bottle labels and wood glue used in furniture. Think about it — if casein can make two objects stick together, imagine what it can do to your sinuses.
To help relieve congestion in your nose and sinuses, try using a neti pot. Not only does it get rid of mucus, but it helps to flush dust and allergens out of your nose that can make you stuffy in the first place.