Because of this inflammation, the airways are very sensitive to things that affect breathing, like exercise, dust, and smoke. When a person with asthma is around these triggers, it causes the muscles in the airways to tighten and air can't get in.
Doctors think that asthma is inherited, so they ask about family history. They also perform breathing tests and, sometimes, allergy tests and x-rays.
There is no cure, so people with asthma have to avoid what triggers their attacks. Some medications are used to stop the symptoms right away, while others work to keep attacks from happening.