Most of the time, panic attacks occur out of the blue. The worst part is that the person suffering from a panic attack fears it will happen again soon. For some people, panic attacks happen only once. However, there are many people who experience repeated episodes.
If you realized how powerful your thoughts are, you would never think another negative thought. Be positive. -- read: http://www.marcandangel.com/2015/09/02/7-ways-to-protect-yourself-from-other-peoples-negative-energy/