Hay fever is the common term used for allergies that occur during certain seasons of the year. Hay fever usually occurs in the spring, summer, or fall.
Some people have hay fever during all three seasons.
Seasonal allergy symptoms are reactions of your body to substances that the body perceives as foreign. Substances that cause an allergic reaction are called allergens. The allergens causing hay fever float in the air and are spread by the wind. The two main types of seasonal allergens are pollen and molds. The type of pollen present depends on the growing season and the area of the country.