When you inhale pollen, dust, or other particles you are allergic to, the sinuses swell because they are trying to remove the allergens. The sinuses get inflamed when you have allergies, and the sinus cavities may become blocked.
One of the most common symptoms of allergies is rhinitis, an inflammation of the moist tissue lining the nasal cavity that causes swelling and congestion inside your nose. Swollen mucous membranes reacting to allergens like pollen are often the reason behind a serious case of the sniffles.
The nose is like a filter for the body, and sneezing is a reflex the body uses to remove tiny bits of blockages in the nostrils. When any small particles like pollen, dust, or anything you are allergic to irritate the nasal lining in the nose, they cause an unpleasant tickling sensation — and you sneeze.
Coughing is another way for the body to get rid of foreign particles, irritants, and allergens from the throat and lungs. Coughing, by forcing air out of the lungs under high pressure, removes substances that don’t belong in the lungs. Inhaling pollen or anything you’re allergic to causes the lungs to overreact and cough to remove them.
The body produces tears to keep the eyes lubricated, as well as to help remove any foreign particles. Sometimes, however, the body produces too many tears, resulting in watery eyes, also called epiphora. Tear over-secretion may be caused by irritation or inflammation of the surface of the eye, which may be caused by allergies.