Why does carpet cause allergies in some people?

Just about anything can find its way into the welcoming fibers of your carpet. Dust mites and pet dander are two major sources of some of the most aggravating allergens, but other irritants such as dust, mold, dirt and pollen tracked in from outdoors regularly build up as well.

If you have a persistent allergy, then you're probably no stranger to dust mites. These microscopic arthropods may be the most common cause of year-round allergies. According to the Asthma and Allergy Foundation of America, more than 20 million Americans are allergic to these little buggers. Technically, the dust mite's waste is the actual allergen, and they emit impressive amounts of it. Dust mites produce up to 200 times their body weight in waste each day [source: Asthma and Allergy Foundation of America]. Dust mites hide deep in carpeting, bedding and furniture, especially in warm, humid environments. Regular cleaning is no match for them either: 95 percent may remain even after vacuuming [source: Asthma and Allergy Foundation of America].

Cuter than dust mites, but perhaps no less aggravating to your allergies are Fido and Fifi. Your dog and cat, precious as they are, provoke allergies in 15 percent to 30 percent of people with allergies [source: Asthma and Allergy Foundation of America]. Their saliva, urine and other secretions contain proteins that are potential allergens, while their hair often traps dust, fleas and pollen that gets lodged in carpeting when the animals shed. The dead skin, or dander, of our furry friends also collects on surfaces like carpet. Pet allergens are especially problematic because they're sticky and cling to surfaces, and when they're disturbed, they hang out in the air for a long time. Even people who don't own pets get exposed to pet dander because it hitches rides on clothing.

Aside from dust mites and man's best friends, mold can be another common cause of indoor allergies. High humidity, spills that aren't cleaned up and leaky ceilings (or dogs) can all contribute to mold growth. Even shampooing or damp cleaning your carpet can promote the spread of mold and mildew if you don't dry it thoroughly. Whenever the source of the mold is disturbed, the spores are dispersed throughout the air.

Finally, anything that you might be allergic to outside could also become a potential problem inside. As you traipse into your living room after a nice walk through your yard, you may also be bringing in loads of pollen and dust. Where does that pollen and dust go? It goes right to the party that the dust mites and dander already have under way.

Learn how to break up this party on the next page.

You've established that your lovely, cozy carpet is making you sneeze. What can you do, aside from ripping it out and starting over with hardwood floors? Unfortunately, if you have severe allergies, this may be your best and only option, according to the Asthma and Allergy Foundation of America. If your allergies are less severe, you have a few alternatives to this spartan approach.

First, if you insist on carpet but haven't picked it out yet, do your allergies a favor by choosing one with a short, tight weave rather than long, loose fibers. The shorter the carpet fibers and the more tightly woven they are, the less inviting the carpet will be to allergens and the easier it will be to clean. Alternatively, you can select smaller machine-washable rag rugs or carpet tiles that can be washed in the hot water necessary to kill mites and other allergens.

If you're stuck with your current carpet, you can still try a few remedies to ease the sneeze. You probably already know that vacuuming is a good place to start. But what you may not realize is that there's actually a right and a wrong way to vacuum. Wrong: cursorily going over the carpet a few times a month with the model you inherited from your grandmother. Right: investing in a model with tight connections (to prevent allergens from escaping) and a built-in HEPA filter and vacuuming thoroughly one to two times a week. (A high-efficiency particulate air filter is designed to remove 99.97 percent of airborne particles.) If you have severe allergies, try to hand off vacuum duty to someone who doesn't or wear a dust mask.

Beyond vacuuming your carpet thoroughly and regularly, you should also have it professionally cleaned with either steam cleaning or dry cleaning every six months. Make sure it dries completely afterward so the dampness won't attract mold or mites. Cleaning up any spills promptly will also help to prevent the growth of mold. Another step you can take to reduce carpet allergens is to request that visitors entering your home remove their shoes to keep from bringing in foreign substances.

By following some of these recommendations listed here, you and your neighbors may make it through a meal without constant sniffles and sneezes.

To learn more about carpet and the allergies it may encourage, try some of the links on the next page.