Inexplicable panic and fear can be seen in a variety of situations: 1. Recent traumatic stressful events, such as facing a big exam, illness of family members, etc. 2. Tiredness, poor rest or stressful life and work. 3. Phobias, anxiety disorders: manifested as panic, fear, anxiety, etc. 4. Angina pectoris or myocardial infarction and other diseases, symptoms such as myocardial ischemia. 5. Hyperthyroidism: in addition to panic and fear, can appear as food hyperactivity, hand trembling, etc. 6. 6. Pheochromocytoma: It may manifest as paroxysmal or persistent increase in blood pressure, panic, chest tightness, fear, etc.