What is hay fever? Hay fever (allergic rhinitis) is your body’s response to an allergen, such as pollen, dust or mold. Symptoms of hay fever include a runny nose, congestion, sneezing, watery eyes, itching, and coughing. Though symptoms of hay fever are similar to those of a common cold, hay fever symptoms usually last for longer periods of time or appear only after exposure to a specific allergen. Up to 30% of children and adults in the United States suffer from hay fever symptoms. If you have hay fever, your body interprets an allergen that it is exposed to, such as pollen, as a foreign intruder and mounts an immune response. In essence, it is as if your body is fighting the allergen as if it were a bacterial or viral infection, which results in the symptoms of a cold. The most common types of allergens responsible for hay fever include tree pollens, grass, ragweed, and mold. Your symptoms may change when the amount and type of allergens change, depending on the time of year, your location, and the weather. Various media outlets in your area may publish daily levels of common allergens like tree pollen or grass pollen, which may help you cope with hay fever. Though inconvenient and sometimes uncomfortable, hay fever is usually not a life-threatening or severe medical condition. For many people, effective treatment includes avoiding the allergens that trigger the body’s immune response and taking prescription antihistamines, decongestants, or steroids. In severe cases, allergy injections may be required. Seek prompt medical care if you are being treated for hay fever and are having trouble breathing, or if symptoms recur or are persistent despite treatment.