If there's one thing we know about panic, it's that it can come out of the blue and even wake people up from a sound sleep. There may be lots of reasons why this happens, but as far as I know, no one has found the single reason. There are also lots of medications that are used, but each person is different and no one medication works for everyone. This would lead me to believe that panic is more complex than anyone really knows.
We do know that there may be a brain hormone involved in this and that it may suddenly spark panic attacks. But the reason for this is a mystery. We also know that severe anxiety, which may fuel panic, can come from a build up of stress.
Stress is something that we can manage and I would suggest that you begin to look at different ways of helping yourself all through the week. One of the ways that has been found quite helpful in managing stress and anxiety (whether you realize the stress is present or not) is simple, regular exercise such as taking long walks, walking in place, walking up and down stairs, or doing any other type of simple exercises. If you work in an office you can even exercise while sitting in your chair. All of it helps.
Another thing that you can do is to use relaxation breathing and we do have a video tutorial on this in our Tips column. Breathing in this manner and using this technique can be quite helpful.
Another thing you want to look at is your diet and how much sleep you're getting because sleep is absolutely essential in controlling anxiety and stress.
Before you begin to think that it might just be a question of using self-help techniques, I would recommend that you have a medical exam with your PCP just to ensure that there isn't a medical process going on here. Once that is cleared up and, if everything is found to be fine, then you might want to try these conservative self-help techniques.