Severe Asthma: Understanding your Diagnosis


Today there are 8.4% of Canadians living with asthma. 5% of them have a diagnosis of severe asthma. A diagnosis of severe asthma can be overwhelming for you and your loved ones.

Asthma is a chronic illness which means it will always affect your lungs and there is no cure.

Proper medication and self-management skills can help most people gain control of their asthma.

Today’s blog will introduce you to a valuable guide that can help you make sense of your diagnosis and what steps you can take to help manage your severe asthma.

Why is Severe Asthma different from mild-moderate asthma?

If you receive a severe asthma diagnosis, this means your asthma requires high doses of medication such as inhaled corticosteroids and others to control symptoms and prevent flare ups (sudden severe worsening of symptoms).

Even with proper medication and addressing all modifying factors that can influence your severe asthma it is still poorly controlled.

Flare-ups can be severe and life threatening. Quality of life is significantly impacted, and daily symptoms can be debilitating.

Being diagnosed with mild-moderate asthma on the other hand will not require such high doses of medications to control symptoms.  Asthma does not present daily symptoms or prevent you from accomplishing everyday tasks and being physically active.  Flare-ups and the risk of death are greatly reduced.

How Severe Asthma affects your lungs

When we breathe, air goes in and out of our airways unobstructed. 

There can also be more mucus inside the airways which restricts the flow of air in and out of your lungs. 

Airways are surrounded by tiny muscles that wrap around them and can spasm and become tight, making breathing harder.  

All these factors combined (inflammation, mucus and tight muscles) that are present with severe asthma mean that airways are blocked and airflow is limited. 

Respiratory system airways
The following symptoms are present, often daily and range from moderate to severe:
  • Severe cough (with or without mucus production)
  • Shortness of breath
  • Chest tightness
  • Wheezing
  • Is your asthma under control?

    There are several factors we can look at to see if your asthma is under control:

    ✅ Daytime symptoms are present 3 times a week or less.

    ✅ Asthma symptoms do not make you miss school, work or other activities important to you.

    ✅ Asthma does not keep you from exercising or other physical activities.

    ✅ Asthma does not disturb sleep.

    ✅ You need your reliever (rescue medication) less than 4 times per week.

    Different types of severe asthma

    There are several different types of severe asthma, so how is it diagnosed? 

    Your doctor and healthcare team will review your medical history (age, gender, flare-ups, other medical issues, types of inflammation found in your airways and blood) and lung function test results to classify and help diagnose your severe asthma.

    Classifying your type of severe asthma is very important because it helps your doctor decide what medications can help you.  There are at least 3 types of severe asthma:

    1. Allergic asthma
    2. Eosinophilic asthma
    3. Non-eosinophilic asthma

    Allergic Asthma

    With allergic asthma, symptoms get worse when exposed to an allergen such as pet dander or pollen. The immune system will react to the allergen and cause swelling in the airways. 

    We all have a chemical protein in our bodies called IgE. With allergic asthma the body will make more of this protein when exposed to an allergen. As a consequence, two things happen; the airways become irritated, swollen and full of mucus and those muscles around the airways tighten. All this makes it harder to breathe.

      Eosinophilic and non-eosinophilic asthma

      Eosinophils are a type of white blood cells that play a role in the immune system and can cause swelling in the airways. 

      When you have severe eosinophilic asthma there will be more eosinophils found in your entire body including your lungs which makes asthma more difficult to control.

      With non eosinophilic asthma, there are no eosinophils in the body and can be eliminated as the main cause of difficult to treat airway inflammation.

      Living Well with your Severe Asthma

      You can live well with severe asthma. You will find a lot of valuable information in the “Living Well with Severe Asthma” program, created by medical experts and people affected by this disease. 

      Following the program in collaboration with medical advice has helped many patients achieve their health and lifestyle goals.

      For more information on understanding your severe asthma diagnosis visit the following module: Understanding a Diagnosis of Severe Asthma.

      Lastly, sign up for our newsletter to receive the latest information regarding severe asthma and lung health.


      About the author

      Katrina Metz is currently working as a consultant for RESPIPLUS, striving to improve education in the respiratory domain for healthcare professionals and patients alike. She has over 16 years experience working as a respiratory therapist and clinical research coordinator for the Research Institute of the McGill University Health Center.

      Katrina Metz