A person often feel overwhelmed and at a loss as to how to cope. This has a knock on effect in that the person begins to dread another attack and so the fear and anxiety of future attacks increase. A person then not only fears the situation that caused the attack in the first place but fears an attack itself. The fear of having panic attack then begins to become their cause and a snowball effect begins.
The trick to coping with panic attacks is to allow them. If a person resists the attack then the attack will build stronger. It's like a rush of water being blocked and then the pressure increasing, once the water is allowed to run freely again the pressure will reduce and pass. Panic attacks do not last, they are by their nature impermanent. They will ebb and flow. If they are not resisted they will pass quickly.
Usually the person will judge an attack as bad and a resistance will arise causing the attack to last longer. If the person is open to what is happening and is aware that this is just a strong emotion that is passing through and does not need to be judged the likelihood is that the attack will pass quickly.
We are human beings and thus will experience a wide range of emotions throughout our lives. The more willing we are to feel emotions fully the less of a problem they will be. Feelings are to be felt, they will then be self liberated. We do not need to control feelings. We can allow them to exist as they are and this is the key.