Hay fever is an allergic reaction indicated by a collection of symptoms, predominantly in the nose and eyes, caused by airborne particles of dust, dander, or plant pollens in people who are allergic to these substances.
When these symptoms are caused by pollen, the allergic reaction is commonly known as "hay fever", but is more technically termed allergic rhinitis. The pollens that cause hay fever vary by person and region. Large, visible pollens are less responsible for hay fever than tiny, hard to see pollens. Examples of plants commonly responsible for hay fever include:
- Trees (deciduous and evergreen)
- Most flowers
Symptoms vary from itching, swelling, and mucus production to hives or other rashes. Most symptoms can be easiliy treated, although more severe symptoms may require allergy shots or removal of tissue in the nose (e.g., nasal polyps) or sinuses.