WHAT IS ASTHMA?
Asthma is a chronic lung disease affecting your airways, the tubes that carry air to and from your lungs. Asthma makes breathing difficult in one or both of the following ways:
Bronchoconstriction (or squeezing) of the airways
During bronchoconstriction, muscles outside the airways tighten, causing less air to pass through and making it difficult to breathe.
Inflammation (or swelling) of the airways
When the lining of the airways becomes swollen or inflamed, mucus forms, blocking airways and making it hard to breathe. Because swelling can occur every day and mucus can build up gradually over time, you do not always feel symptoms from inflammation.
Common asthma symptoms include wheezing, coughing, shortness of breath and chest tightness. These and other symptoms vary from person to person. If you have any of these symptoms, it’s important to consult with your health care provider.
Asthma flare-ups are sometimes called asthma episodes or asthma attacks. Asthma flare-ups may prevent a person from being able to do what he or she normally does each day, like go to work or school. Asthma is the leading cause of school absences due to chronic illness, accounting for an estimated 13.8 million missed school days each year.
An asthma diagnosis often requires a thorough medical history and breathing tests. Spirometry is a breathing test that measures how much oxygen you inhale, how much you exhale and how quickly you exhale.