Hay fever, a common condition in the United States, affects people of all ages. "Hay fever is a generic term for a pollen allergy," explains Timothy Craig, D.O., an allergy researcher and associate professor of medicine at Pennsylvania State University Hershey Medical Center. People who have hay fever also may experience somnolence (sleepiness), poor sleep, wheezing, and a dry throat. New allergy sufferers may think they have a cold until noticing that the same "cold" reoccurs each spring, summer, or fall.
Allergies develop when the immune system perceives airborne tree, grass, and weed pollens -- items which are normally harmless -- as invaders. The immune system reacts by developing antibodies or sensitized cells that produce a host of protective chemicals, including histamine, to fight off perceived threats. This defense triggers congestion, stuffiness, and sneezing. The more you come in contact with allergens (the substances causing the allergy) the more "sensitized" you become, increasing your odds of suffering an allergic reaction.
Each springtime allergen has a pollinating period that follows the same schedule year after year. "People usually have multiple allergies. If they are bothered in the spring, they will most likely have fall allergies as well," says Norman Edelman, M.D., a pulmonologist and scientific consultant to the American Lung Association.
Common indoor allergens, such as mold, animal dander, or the droppings of cockroaches or house mites, may trigger allergic rhinitis. This condition is called a perennial allergy because it occurs year-round.
Studies show that if your parents have allergies, you may suffer too. Allergies can reappear after years of remission, and they can develop at any time. The severity of the symptoms seems to diminish with age.