They are real. They are physiological. They are not trivial. Panic sufferers experience real symptoms. The problem is that the panic sufferer is afraid of these symptoms.
Panic sufferers are afraid of their anxiety symptoms and sensations.
Because they think of them as dangerous. They are NOT dangerous. However, try convincing a panic sufferer that they are not dangerous. Here is how it happens. The person feels all of the classic panic symptoms and feels like they are going to die or go crazy.