Inflammation of the airways
An Asthma Attack
Doctors are not exactly certain how you get asthma. But they do know that once you have it, your lungs react to things that can start an asthma attack.
For instance, when you have asthma, you might get an asthma attack when you have a cold (or some other kind of respiratory infection). Or, you might get an attack when you breathe something that bothers your lungs (such as cigarette smoke, dust or feathers). In all cases, asthma is a result of inflammation of the airways.
When this happens, three changes take place in your lungs:
Cells in your air tubes make more mucus than normal. This mucus is very thick and sticky. It tends to clog up the tubes.
The air tubes tend to swell, just as skin swells when you get a scrape.
The muscles in your air tubes tighten.
These changes causes the air tubes to narrow. This makes it hard to breathe.
Asthma attacks may start suddenly. Or they may take a long time, even days, to develop. Attacks can be severe, moderate or mild.