Is panic disorder a real entity?

Yes, very real: Panic disorder is a genuine medical condition consisting of episodic intense anxiety & terror that come out of the blue. They're accompanied by physical symptoms such as: racing heart; chest pressure or pain; shortness of breath; feeling weak or dizzy; GI distress; tingling or numbness in hands, fingers, & sometimes face; feeling of loss of control & that death is imminent. Treatment helps!

Panic Disorder: Yes it is real. Sometimes people may assume that emotional problems are "all in your head." the emotions and thoughts we have exert real effects on the body. It is not imaginary. Chemical changes in the brain trigger chemical changes in the rest of the body. In this case, it is the release of adrenaline, the "fight or flight" chemical, at times when there is no real danger. It is treatable.