Allergic rhinitis, commonly known as hay fever, is a chronic inflammatory condition of the nasal passages caused by an allergic reaction to allergens, such as pollen, dust mites, pet dander, or mold spores. It is a common condition that affects people of all ages and can lead to a range of bothersome symptoms, including runny or stuffy nose, sneezing, itchy or watery eyes, throat, or ears, coughing, fatigue, or headaches.