During hyperventilation which takes place as your anxiety increases, you do not allow your lungs to properly expand, you draw in very little oxygen, and you do not exhale enough carbon dioxide. You then start to experience, through such loss of oxygen, light-headedness which is what causes your body to experience more panic because you thinking about how you cannot breathe correctly. Remember, this happens when anxiety in your body increases, so finding a way to control the anxiety can really be the anxiety cure you’ve been looking for. I hope this has been useful and at least somewhat informative. There a lot of information out there. Keep searching.