Panic attacks are almost always associated with shortness of breath or difficulty breathing. When people feel short of breath, they often respond by hyperventilating, another common symptom of panic attacks. People hyperventilating exhale more carbon dioxide than they produce, thereby lowering carbon dioxide levels in the body. As carbon dioxide levels drop, several other changes in the body result in the lightheadedness and dizziness that often accompany panic attacks.*You'd think a little more carbon dioxide in the atmosphere would be beneficial for some people. And that they'd be self-aware enough to recognize it.
*or maybe its just breathing abnormalities