Panic Attack.

A panic attack occurs when an individual body experiences a rush of intense psychological (mental) and physical symptoms. These are sudden, unexpected bouts of intense terror. A person may find it difficult to breathe, and feel their heart beating hard when an individual gets panic attack. They may have a choking sensation and a pain in the chest, begin to tremble or feel faint. It's easy to error these for the marks of a heart attack or another serious problem. What differentiates panic attacks from a natural response to real danger is that, panic attacks can occur at any time.

If a person gets panic attack, it doesn't necessarily mean that the person will have it again. But, sometimes, because of what people went through, they become afraid of having another. This fear may actually initiate another attack when a similar situation arises.