Answer:
1. Airway Blockage/Obstruction
2.Scarred lung tissue
Step-by-step explanation:
If your airways are blocked by anything ranging from mucus to a tree sapling (this can happen lol), it will prevent you from breathing normally, and it will be harder for you to take a breath after exercising, for example. Scarred lung tissue is an issue that comes from pre-existing conditions, such as asthma, and what happens with this is that, due to so much strain on your lungs, they can get injured or collapse, and after some time, the injuries on the tissue will cause it to harden, which means your lungs will not be able to expand and contract properly.