Please note: This information was current at the time of publication. But medical information is always changing, and some information given here may be out of date. For regularly updated information on a variety of health topics, please visit, the AAFP patient education website.

Information from Your Family Doctor

Things That Can Cause Asthma and Allergies


Am Fam Physician. 2002 Aug 1;66(3):429-430.

Dust mites

Controlling dust mites is the most important thing you can do in your house to make your asthma and allergies better. Dust mites are tiny bugs that cannot be seen. They live in places that collect dust. Pillows, mattresses, and carpets usually have thousands of dust mites living in them. People can become allergic to dust mites and their waste products. To control dust mites you should:

  • Cover your pillows and mattresses with vinyl or semipermeable covers.

  • Wash your sheets, pillowcases, and comforters every one to two weeks in hot water (at least 130°F).

  • Remove carpet from the bedroom or carpet that is laid over concrete.

  • Avoid lying or sleeping on upholstered furniture.

  • Clean uncarpeted floors with a wet mop every week.

  • Reduce indoor humidity to 50 percent or less.


Pets can sometimes cause allergy problems. People can become allergic to parts of the animal's skin, saliva, and waste products. Your doctor can do tests to see if you are allergic to your pet. If you are, you should:

  • Permanently remove your pets from the house. This is the best way to make your asthma and allergies better.

  • Keep pets out of the bedroom and off of carpet and upholstered furniture, if you're unable to remove them.


Some people are allergic to cockroaches. To get rid of cockroaches you should:

  • Keep the kitchen very clean.

  • Avoid leaving food or drink out.

  • Use pesticides to kill the cockroaches, if necessary.

Pollens and outdoor molds

Pollens and outdoor molds come and go depending on the weather and time of year. To avoid pollen and outdoor molds you should:

  • Find out when the pollen and mold counts are high in your area. These counts can be found on your local TV stations and allergy Web sites (see Resources).

  • Avoid going outside when pollen and mold counts are high.

Indoor molds

Indoor molds need moisture to grow. To control indoor mold you should:

  • Fix all water leaks and damp areas associated with mold growth.

  • Use a dehumidifier to keep your basement dry.

  • Reduce the humidity in your house to 50 percent or less.


If you have asthma, you should avoid all exposure to tobacco smoke.

Air pollution

Don't exercise outdoors when pollution levels are high.


Here are some resources for more information about asthma and other allergies:

American Academy of Allergy, Asthma and Immunology (AAAAI)

Web site:

American Academy of Family Physicians

Web site:

American College of Allergy, Asthma & Immunology

Web site:

Asthma and Allergy Foundation of America (AAFA)

Telephone: 800-7-ASTHMA (1-800-727-8462)

Web site:

National Asthma Education and Prevention Program (NAEPP)

Web site:

This handout is provided to you by your family doctor and the American Academy of Family Physicians. Other health-related information is available from the AAFP online at

This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.


Copyright © 2002 by the American Academy of Family Physicians.
This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP. Contact for copyright questions and/or permission requests.

Want to use this article elsewhere? Get Permissions

More in AFP

Editor's Collections


May 2022

Access the latest issue of American Family Physician

Read the Issue

Email Alerts

Don't miss a single issue. Sign up for the free AFP email table of contents.

Sign Up Now

Navigate this Article