This obstruction is reversible. That means that the airways are blocked sometimes but generally not all of the time. This reversibility is the hallmark of asthma, along with inflammation of the airways. To make the diagnosis, we typically look at spirometry, which is a measure of the ability to exhale air. We look for people to be able to reverse their obstruction by about 15 percent.
Asthma attacks can occur at variable intervals.
Some people will have an attack only a year or even less frequently. Other people will have almost constant attacks. There are a wide variety of asthma triggers. We have three cats, and we dust and vacuum only once a week. Cat dander is a very potent allergy.