Hay fever, also known as allergic rhinitis, is an allergic reaction that occurs when the immune system overreacts to airborne allergens, such as pollen from trees, grasses, and weeds. Common symptoms include sneezing, runny or stuffy nose, itchy eyes, and fatigue. It typically occurs during specific seasons when pollen levels are high. The condition can be triggered by various allergens, and its severity can vary from person to person. Treatment options include over-the-counter antihistamines, nasal sprays, and allergy shots. Avoiding exposure to allergens, such as staying indoors on high pollen days, can also help manage symptoms.