May also be called: Hay Fever; Seasonal Allergic Rhinitis; Seasonal Allergies

Allergic rhinitis (often called "hay fever" or seasonal allergies) are allergy symptoms that occur during certain times of the year, usually when outdoor molds release their spores or trees, grasses, and weeds release tiny pollen particles into the air to fertilize other plants.

More to Know

Allergic rhinitis causes symptoms such as sneezing, stuffiness, runny nose, and postnasal drip. Because it's commonly called "hay fever," you might think it's only related to outdoor or seasonal allergies, but many indoor allergens also cause it.

Allergies to pollen, dust, mold, and many other allergens (substances that cause allergic reactions) often begin in early childhood. The immune systems of people who are allergic to mold spores or pollen treat these allergens as invaders and release chemicals, including histamine, into the bloodstream to defend against them. It's the release of these chemicals that causes allergy symptoms.

Exposure to allergens causes inflammation in the nose and upper respiratory system.

Keep in Mind

There is no real cure for seasonal allergies, but it is possible to relieve symptoms. Start by reducing or eliminating exposure to allergens. During allergy season, keep windows closed, use air conditioning if possible, and stay indoors when pollen counts are high.

People with seasonal allergies should wash their hands or shower and change clothing after being outside, and should not mow the lawn, as this kicks up pollen and mold spores.

If reducing exposure isn't possible or effective, medicines can help ease allergy symptoms. If symptoms cannot be managed with medicines, a doctor may recommend seeing an allergist or immunologist for regular allergy shots (immunotherapy), which can help desensitize someone to allergens.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.