Allergic rhinitis, also called hay fever, is an allergic reaction that causes sneezing, congestion, itchy nose, and watery eyes. Pollen, pet dander, mold, and insects can lead to hay fever symptoms. When you breathe in allergens through your nose or mouth, your body reacts by releasing a natural chemical called histamine. Despite being called hay fever, hay doesn’t cause hay fever, and most people don’t get a fever.

Source: Cleveland Clinic