Could a random full on panick attack with hyperventilating be the cause of something physically wrong with the body ? or is it always only mental?

Usually not: Panic attacks can be stimulated by a variety of triggers, physical, emotional and mental. The triggers are not always easily identifiable or clear. They can come out of nowhere and be triggered by sights, sounds, smells, emotional responses, etc. Hyperventilating without signs or panic or typical triggers can be from the body trying to blow off more carbon dioxide. This is unusual, however.