Allergic rhinitis, or “allergies,” is a reaction that happens when your body’s immune system overreacts to something in the environment. In short, your immune system reacts to a generally harmless environmental trigger as if it were a threat, like a virus. The symptoms of allergies often mimic those of a cold, and may include sneezing, runny or stuffy nose, coughing, fatigue, and headache.

Year-round allergies result from indoor triggers in most cases. Seasonal allergies are normally caused by outdoor triggers such as pollen. The following sections describe some of the most common environmental factors that may be causing your persistent, year-round allergies, and how to avoid them.

Pet Dander

Dander is made up of tiny bits of dead skin that flakes off of animals. It can be found in the air and on surfaces that come into contact with pets. Because of its microscopic size, light weight, and rough edges, dander sticks easily to clothing, furniture, and carpet, making it easy to spread. 

If you know you’re allergic to pet dander and thinking of getting a pet, know that cats are about twice as likely to aggravate allergies as dogs, according to the American Lung Association. Dog breeds are not all the same, however, and there are some “hypoallergenic” dog breeds out there. The American Kennel Club lists dogs such as poodles and schnauzers as being safer options for allergy sufferers. If you already have a pet, be sure and bathe it weekly. Cut down on dander and hair around your home by vacuuming often and keeping pets off the furniture.


Mold likes to grow in damp places, like bathroom walls and flooring, in and around air conditioners, in basements, and even in refrigerators. Houses that have poor ventilation and high humidity are the most prone to mold problems, and mold could be hiding anywhere in the right conditions.

To prevent the growth of mold, keep damp areas well ventilated, and use bathroom exhaust fans while showering. A dehumidifier should be placed in any areas that smell musty. Make sure you clean the dehumidifier’s filters and coils regularly. Repair any sources of moisture that you can, such as leaky pipes. Make sure gutters and other drainage areas on and around your home are kept clear.

Dust Mites

Dust mites are tiny bugs that live in household “dust.” These bugs feed on human skin cells and moisture in the air. The mites’ bodies, saliva, and feces also make up part of the dust; in fact, it’s these parts that cause the allergic reaction. 

To keep dust mites away, keep zippered plastic covers on mattresses and pillows, and wash all linens in hot water. Remove carpet in your house and replace it with tile or wood floors. Wash area rugs in hot water on a monthly basis. Use hard window coverings, such as blinds, rather than curtains or valances. Make sure your vacuum cleaner has a HEPA filter installed, and follow instructions carefully for cleaning or replacing filters.


Other insects, particularly cockroaches, can be major sources of allergens. These allergens come from the feces, saliva, and tiny particles of the insect’s body, and can be inhaled like any other allergy trigger. According to the Allergy and Asthma Foundation of America (AAFA), if you see one cockroach in your home, you can safely assume that there are least 800 more hiding nearby. 

Cockroaches are notoriously hardy, and thus can be difficult to get rid of. They thrive in almost any condition, but they do prefer areas with moisture and food readily available. To help prevent an infestation, don’t leave food out (even pet food) and clean up crumbs immediately. Seal cracks in walls and floors that could allow entry, and fix or clean up any sources of moisture.

Preventing or minimizing your exposure to allergens in your environment is key to managing your allergy symptoms. The more you know about the environmental triggers that affect your symptoms, the more you can do to stay healthy and feel well.