Hay fever, also known as allergic rhinitis, is an allergic reaction that occurs when the immune system overreacts to airborne substances like pollen, dust mites, or pet dander. Common symptoms include sneezing, runny or stuffy nose, itchy eyes, and fatigue. It often occurs during specific seasons, particularly in spring and fall, when pollen levels are high. The condition affects millions of people worldwide and can significantly impact daily life. Treatment options include over-the-counter antihistamines, nasal sprays, and allergy shots. Avoiding known triggers, such as staying indoors on high pollen days, can also help manage symptoms effectively.