Asthma is a chronic disease of the lungs.  We use our lungs to breathe, so the most common symptom of asthma is trouble with breathing.  People with mild asthma will have trouble breathing only once in a while.  People with more serious asthma will have breathing problems more often, sometimes every day.  Chronic is a word that means “to last a long time” or to “happen over and over again”.  This means that asthma is always there – even when a person with asthma is not having any trouble breathing.

The basic problem in the lungs of people with asthma is that the breathing tubes get blocked.  When the breathing tubes are blocked, it is hard for air to go in and out of the lungs and this causes trouble breathing.  We know a lot about what causes the breathing tubes to get blocked and what is going on in lungs of someone with asthma.  For more information see What Happens in the Lungs in Asthma.

WHY DO PEOPLE GET ASTHMA?

We don’t know why people get asthma.  We do know that asthma usually runs in families.  Many times other allergic diseases, such as nose allergies (“hayfever”) or eczema, also run in the family of children with asthma.  Sometimes only other allergic diseases and not asthma run in the family of a child with asthma. 

Asthma is not contagious. You can’t “catch” it from someone like you can catch a cold.  Asthma is not a “psychological” disease and people don’t develop asthma because of “stress” or “anxiety”.  There is nothing that a mom can do during pregnancy that can cause her child to develop asthma.

We think that people get asthma because of many reasons that happen together.  First, there is usually asthma and/or allergies that run in the family (a genetic risk).  Then a person who has a genetic risk gets exposed to things in their environment that cause allergies (such as dust mites, pet dander or pollens, to name a few) or have infections or other exposures that increase their chance of getting asthma (an environmental risk).  It is this combination of genetics and environment that helps cause the asthma to start.  Most of the time there is no way to tell exactly what combination of factors caused a particular person to start having asthma.  There are people who have asthma who don’t have a genetic risk.  There are some people with asthma who are not exposed to things in the environment that are known to cause asthma.  We have a lot to learn about why people get asthma.