Indoor Allergies Health Center

Indoor allergies stem from allergens, triggers that cause the body's immune system to react defensively, fighting what it believes to be harmful even though it is not. Indoor allergens can include substances such as pet dander, mold, dust mites, cockroaches, and cigarette smoke.

Fifty-two percent of U.S. households have at least six detectable allergens hiding inside with 46 percent of U.S. households having three or more allergens at increased levels.

Symptoms of indoor allergies may include mild reactions such as sneezing, coughing, skin irritation, and a runny nose. Symptoms of an allergen like cigarette smoke could include more moderate reactions like burning or watery eyes, nasal congestion, hoarseness, and shortness of breath.

Allergens can be sneaky and lie in wait where you least expect them. If you find yourself having reactions to pet dander and animals, you may have a reaction at school or in public buildings, even where there are no pets.

Indoor allergies may also come as a result of some unexpected causes such as indoor humidity. Homes with humidity above 60% have 3-4 fold higher mean bed dust mite allergen than those homes with humidity levels below 60%.

Review Date: 
April 19, 2012
Last Updated:
July 1, 2013