People with lung conditions like chronic obstructive pulmonary disease (COPD) and asthma often experience breathlessness due to changes in their airways. But sometimes the way that you breathe can also contribute to breathlessness.
Your diaphragm is your big breathing muscle. It is dome-shaped and sits below your ribs. As you breathe in, your diaphragm contracts and flattens down and air is drawn into your lungs. As you breathe out, your diaphragm relaxes up into a dome shape again. When it contracts down for your breath in, it squashes onto your tummy and makes your tummy push out; that is why diaphragm breathing is sometimes called tummy breathing. When you are breathing using your diaphragm, there is very little movement in your chest. You will mainly just see your tummy rise and fall with each breath in and out.
Image courtesy of BasicPhysiology.com
Accessory breathing muscles
In addition to the diaphragm, we also have little breathing muscles around our upper chest, known as the accessory breathing muscles. They lift and open your upper chest. These muscles are there for when we need more air than our diaphragm can pull in, for example when you are exercising.
Sometimes people get into a habit of using their accessory muscles to breathe most of the time, even when at rest. This is known as dysfunctional breathing. If you are breathing like this, you will see your chest rise and fall with each breath in and out (rather than your tummy). Dysfunctional breathing can make you feel breathless because your accessory muscles are much smaller and less efficient than your diaphragm.
People with lung conditions often need to use their accessory muscles to breathe when they are symptomatic (eg. if they are unwell or their asthma has been triggered) and this is a normal reaction. But it is important to return to relaxed tummy breathing if possible, once the episode has passed.
Certain lung conditions (for example emphysema) make it more difficult to use the diaphragm to breathe because the lungs’ resting size is more inflated than normal. This pushes the diaphragm flat so it hasn’t got as much room to contract. So, people with emphysema have to rely on their accessory muscles to breathe all the time.
Check your breathing
You can check your own breathing pattern by resting one hand on your tummy and one hand on your chest. Which hand is moving? If it is the hand on your tummy, you are using your diaphragm to breathe. If it is the hand on your chest, you are using your accessory muscles.
If you would like to learn more about your own breathing pattern and how to optimise this, you should ask to see a respiratory physiotherapist.
About the author:Zoe Manderson is a respiratory physiotherapist for Te Whatu Ora Taranaki and a member of the Foundation's Scientific Advisory Board.
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