Drink more fluids. Water helps loosen mucus and soothe an irritated throat. Dry, hacking coughs respond to honey in hot water, tea, or lemon juice. Do not give honey to children younger than 1 year of age. Elevate your head with extra pillows at night to ease a dry cough. Try a cough drop to soothe an irritated throat.
That is actually true to a certain extent. Most of the time you need to have some sort of sensitivity/allergy to dairy. But dairy products can increase the thickness of your phlegm, therefore can clog up your sinuses, and eventually cause the sinus pressure.
Sinusitis is inflammation of the sinuses. It occurs as the result of an infection from a virus, bacteria, or fungus. The sinuses are air-filled spaces in the skull. They are located behind the forehead, nasal bones, cheeks, and eyes. Healthy sinuses contain no bacteria or other germs. Most of the time, mucus is able to drain out and air is able to flow through the sinuses. When the sinus openings become blocked or too much mucus builds up, bacteria and other germs can grow more easily. Sinusitis can occur from one of these conditions: Small hairs (cilia) in the sinuses fail to properly to move mucus out. This may be due to some medical conditions.