Allergic rhinitis, often called hay fever, is an overreaction of the immune system to particles in the air that a person breathes. This overreaction causes inflammation and symptoms such as sneezing; a runny, stuffy, or itchy nose; and itchy, watery eyes.

Other symptoms of allergic rhinitis may include a temporary loss of the sense of smell, headache and fatigue, dark circles under the eyes, and mucus draining from the nose down the back of the throat (postnasal drip).

Substances that can cause the symptoms of allergic rhinitis include pollens, animal dander, dust mites, and mold. Substances found in the workplace, such as chemicals and wood dust, can also cause symptoms.

Allergic rhinitis can last for many years. Symptoms can appear only at certain times of the year or throughout the year. They may decrease over time.

There is no cure for allergic rhinitis. Treatment includes avoiding the allergens that cause symptoms, using medicines to control symptoms, and getting allergy shots.