Panic attack is a sudden access of intense fear or anxiety (emotional condition characterized by psychomotor restlessness, obscure fear, without reason) that cause worrisome symptoms, but not life threatening: increased heartbeat, difficulty in breathing, feelings of loss of control or impending death. Ordinarily, the symptoms last from 5 to 20 minutes and can be caused by stressful circumstances, or, just unexpected.
The human body is endowed with the ability to protect from danger or to cope with stressful situations. Panic attack occurs when the protective system react when not needed. Going through a crisis. Your body is focusing on short-term surviving. The level of adrenaline and blood pressure increase, breathing becoming faster. The legs are ready to take the flight, the arms will be strained, as prepared for battle. Pupils are dilated, they get more light. You feel the danger lurking.