Have you, or someone you know, been diagnosed with asthma?   If so, you may wonder – What is asthma?

The medical definition of asthma is simple.  Doctors define asthma as “a chronic inflammatory disease of the airway” that may cause any or all of the following symptoms: shortness of breath, chest tightness, cough and wheeze.

Although the definition is simple, the condition itself is quite complex.  Asthma has no set pattern.  It can be mild, moderate or severe.  It varies from person to person and from one episode to the next. Asthma can flare up from time to time and then you may not be bothered by it for a long period of time.  You cannot predict when your asthma will be troublesome but you can learn how to control your symptoms and your asthma.

“A chronic inflammatory disease of the airway” means that there is swelling/inflammation and mucus inside your airways. The word “chronic” means that this swelling is there to some degree all the time. The more inflammation in the airway, the more difficult it is to move air in and out of the lungs. Inflammation is the major part of the problem with asthma, but it is not the whole story. As the swelling in the airway increases, the lining of the airway becomes very sensitive and small muscles around it start to twitch and tighten. This is called "bronchoconstriction". You may have also heard the term ‘twitchy airways.” Bronchoconstriction can happen without swelling, but inflammation usually occurs first and it can slowly increase over time, so slowly that you might not notice it. If nothing is done to stop the swelling, it can lead to blockage or bronchoconstriction and, potentially, life-threatening breathing problems.

Fortunately, there are ways to avoid asthma triggers and treat asthma symptoms and there are safe medications that prevent and treat the airway inflammation and bronchoconstriction.  Your Healthcare Team can educate you on how you can take control of your asthma and thereby allow you live symptom free and enjoy a high quality of life.

Breathing: Normal Airway versus Asthma Airway

In someone with normal lung function, air is inhaled through the nose and mouth, passes through the trachea (also called the windpipe) and then into the bronchi (large airways). The bronchi turn into smaller and smaller tubes, ending in many small air sacs called alveoli. It's here, in the alveoli, that oxygen (which the body needs), is passed into the blood, while carbon dioxide (which the body doesn't need), is removed and exhaled.

What happens in the airways when someone has asthma symptoms?
We know that with asthma, the flow of air is obstructed as it passes in and out of the lungs. This happens because of one or both of the following:

• Inflammation - The lining of the airways becomes inflamed (irritated, red and swollen) and may produce more mucus. The airways of a person with asthma will usually have some inflammation all the time and if left untreated this inflammation increases and the airway becomes more sensitive which leads to increased asthma symptoms.
• Bronchoconstriction - The muscles that surround the airways become more sensitive which makes the airways twitch and tighten, causing the airways to narrow. (called Bronchoconstriction) This narrowing makes it difficult to get air in and out of the airways. Bronchoconstriction usually occurs because the inflammation is not treated.

For more information about asthma, visit www.asthma.ca