Hayfever
Hay fever or allergic rhinitis is a very common medical problem affecting more than 15 percent of the population,
both adults and children.
Hay fever is an immune disorder characterized by an allergic response to pollen grains and other
substances.
Also known as allergic rhinitis, there are two types:
seasonal, which occurs only during the time of year in which certain plants pollinate,
and perennial, which occurs all year round.
(A related problem, nonallergic rhinitis,
shares symptoms with hay fever but isn't caused by allergies.)
Typically, if you suffer from hay fever in the spring,
you're probably allergic to tree pollens.
Grass and weed pollens may be causing your allergic reaction during the summer.
In autumn, ragweed may plague you,
and fungus spores cause problems from late March through November.
People with year-round (perennial)
hay fever are usually allergic to one or more allergens found indoors.
These include house dust mites, feathers, and animal dander
(the tiny skin flakes animals such as cats and dogs shed along with fur),
all of which may be found in pillows, and bedding, heavy draperies,
upholstery, and carpeting. Another common allergen,
mold, is usually found in damp areas such as bathrooms and basements.
