COPD affects both the lungs and the body. As a result, breathlessness can be caused by a combination of reasons:
- In COPD, the lungs lose their natural elasticity as they become damaged and over-expanded. This can make it harder for someone who has COPD to breathe air out fully.
- As a result of being unable to breathe air out fully, the ‘trapped’ air leads to an over-expansion of the lungs. This is often called a barrel chest (hyperinflation). Hyperinflation changes the way your muscles and chest wall work. The breathing muscles of a person who is hyperinflated will have to work harder and as a result, will fatigue more quickly. Other muscle groups can be used to help people breathe; these muscles are known as accessory muscles. The neck muscles are an example of these accessory muscles.
- The muscles used for breathing, like all muscles in the body, require oxygen to be able to work. A person who has COPD may have a higher oxygen requirement just to continue breathing.
- The narrowing or swelling of the breathing tubes or airways, in combination with producing larger amounts of sputum, can restrict the flow of air in and out of the lungs. Airway clearance techniques (discussed on page 17 of this module) can help to keep the breathing tubes or airways clearer and assist in making breathing easier.
- When you are living with COPD, you may be unable to continue your normal level of activity, which can result in a cycle of inactivity (see the following diagram). Frequently, this will lead you to reduce your physical activities, causing you to become unfit or poorly conditioned. Being unfit or poorly conditioned makes your movements less efficient and requires greater effort to complete everyday activities. Reduced fitness may also make you more susceptible to ‘flare-ups’.
- People who have COPD often experience increased anxiety about becoming breathless or short of breath. This anxiety can lead to a fear of undertaking activities.
In summary, people with COPD need to work harder than others to breathe.