Allergic rhinitis (hay fever) can be brought on at certain seasons by the airborne pollens of trees, grass, and weeds. Other allergens cause hay fever all year. These year-round troublemakers include molds, dust mites, and animal dander.

Hay fever symptoms include sneezing, watery eyes, runny nose, nasal congestion, and an itchy palate and throat. Hay fever can also be accompanied by conjunctivitis (itchy, swollen eyes), malaise, headache, and sinus pain.