Hundreds and thousands of years ago, when humanity was very young, we also came very low down in the food chain. We didn't have big, sharp teeth and claws and we made lunch for a lot of extremely savage, nasty animals.

In those far off times, panic attacks were very useful. At best, we lived in unoccupied caves, so when we went outside in the morning, we were instantly on high alert. If danger threatened, and it frequently did, we had two choices; fight or run. You may well have heard of fight or flight. Those were our choices. They still are. That's why the human mind can trigger a panic attack unconsciously and incredibly quickly.

People who suffer panic attacks often report that they come out of nowhere. The point is that if you're in a situation where you're directly threatened, thinking and working out your best course of action is going to be far too little, far too late. Not only that, but suppose you make the wrong decision? So this is where the unconscious mind takes over.

The other point to remember is that it's far better to respond to danger when there isn't any danger present, than the other way round. Erring on the side of caution is usually the best course! But what is the unconscious mind and what does it do?

Really, we have two minds. The conscious mind. This tells us that it's raining and that we'd better put up our umbrella. Then we see a penny on the ground. We pick it up. "Oh, isn't that a pretty leaf!" says your wife. "I'll collect that in my leaf book."

Then there's your second mind, or your unconscious or subconscious mind. This is far and away more powerful and complex and among millions of other functions, has roles such as looking after our digestion, blood pressure and body temperature. Generally, we're totally unaware that all that's happening.

The panic attack, too, happens pretty much unconsciously, hence the reason for someone saying; "Oh, it came out of the blue." Then, all of a sudden, your body decides to alter its priorities from long term survival to short term, emergency, survival. We've discussed the evolutionary reasons for a panic attack. But what does that have to do with having an attack in the middle of the supermarket? All will be revealed!

But why do you feel so strange? What's happening to your body? Hormones such as adrenaline are released, your breathing speeds up preparing you for some type of physical effort and your blood pressure increases. The blood's pumped away from your stomach and into the large muscles of your arms and legs to prepare you to run or fight. Your palms and feet probably start to sweat so that you're better able to run and grip a weapon.

Because of the blood being pumped away from the stomach, people who suffer regular stress very often experience digestive problems. Now, it's perfectly true that our need for such a violent reaction these days is pretty slim. But imagine this, purely as an example.

You wish to cross the road. You look to your right and it's all clear. When you look left, however, you see a large Mac truck coming fast towards you. Suppose it were left to your conscious mind to decide whether to cross or not? You'd start working out how quickly you could run to the other side. Whether that car you saw in the distance might make crossing impossible. There's a car trying to make a 'U' turn fifty yards up the road... By the time you've actually worked all that out, the chance of crossing has long since gone and a good thing too.

The likelihood is you'd have ended up as part of the road!