Breathing can be hard after you've had surgery, when you have pneumonia or a lung disease like COPD, or if you're on bed rest. You may find that you can only take small, shallow breaths. Breathing this way makes it harder to get air into your lungs and can cause fluid and mucus to build up in your lungs. This could cause a serious lung infection like pneumonia.
Using an incentive spirometer can help you practice taking deep breaths, which can help open your airways, prevent fluid or mucus from building up in your lungs, and make it easier for you to breathe.