2. Reduced Lung Capacity
The amount of air that you can hold in your lungs can actually be reduced as a result of asthma. This occurs as a result of a combination of the narrowing of your airways (making it difficult to breathe in as much air in the same time frame as normal), and an increase in the amount of mucus in your trachea. This combination means it’s difficult to hold as much air in your lungs as normal before needing to breathe in and out again.
You’ll notice this on your peak flow, a device given to people with asthma to measure their capacity. When your airways tighten, you should notice a negative effect on your peak flow.