Why does anxiety make me feel like something bad is about to happen?

When I teach people about anxiety, I usually take them on a little bit of a time-travelling adventure and introduce them to my friend Dave the caveman.

Bear with me on this one. Dave is going to help this make sense.

Meet Dave

I want you to imagine what life might have looked like for Dave. Quite basic, quite primitive and, importantly, quite dangerous.

Dave's brain didn't have to worry about work deadlines, exams, presentations, whether somebody was annoyed with him because they hadn't replied to his message, or what that slightly strange sensation in his chest might mean.

Dave had rather more immediate problems. Finding food. Staying warm. Avoiding predators. Generally trying not to die.

So, unsurprisingly, Dave's brain became very good at keeping him safe. In fact, as far as his brain was concerned, survival was pretty much job number one.

There were a couple of things that helped with this. One was other people. Dave lived in a tribe, and there was safety in numbers. If Dave went out hunting with a group of other people, he was much more likely to survive an encounter with a sabre-toothed tiger than if he'd decided to wander off into the wilderness on his own.

This is one of the reasons our brains care so much about other people and what they think of us. For our ancestors, being accepted by the group wasn't just nice - it was connected to survival.

The other incredibly useful thing Dave's brain could do was notice danger.

And it could do it very, very quickly.

Imagine this...

Dave and his friends are sitting around the campfire one evening. Everything is quiet and then, somewhere in the darkness, Dave hears a twig snap.

What does his brain do?

It doesn't say, ‘Hmm. That's interesting. There are probably several possible explanations for that noise. Let's gather some evidence before jumping to conclusions.’

It says:

Tiger. RUN!

Or the caveman equivalent.

And that's a really good thing!

Because if there actually is a sabre-toothed tiger in the bushes, Dave doesn’t have time to weigh up all the possible explanations. He needs his body to be ready to do something about it.

So his threat system kicks in.

Adrenaline and other stress hormones are released and all sorts of things start happening in his body. His heart beats faster. His breathing changes. Blood is directed towards the muscles he's going to need if he has to run or fight. Digestion becomes rather less important because, frankly, digesting dinner isn't much use if you're about to become dinner.

Even his attention changes. His brain becomes much more interested in anything that might signal danger.

We call this the fight-or-flight response.

And here's something I really want you to remember: there's nothing wrong with it.

It's doing exactly what it's supposed to do.

In fact, you and I are here today because generation after generation of our ancestors had brains that were good enough at spotting danger to keep them alive.

So anxiety itself isn't the problem.

The problem is that we're not Dave

Fast-forward thousands of years and most of us are no longer worrying about sabre-toothed tigers.

Unfortunately, nobody appears to have told our brains.

Our threat system can be activated by something dangerous happening in front of us, but it can also be activated by the thought that something bad might happen.

And this is where things get interesting.

Your thought might be:

I'm going to completely mess up this presentation and everyone will think I'm an idiot.

Or:

I'm going to fail this assignment and get kicked off my course.

Or:

What if this headache means there's something seriously wrong with me?

There isn't a tiger.

But your brain has detected a threat.

And once it thinks there's a threat, it does what thousands of years of evolution have taught it to do.

Your heart starts racing. You feel hot. You sweat. Your stomach starts doing strange things. Your muscles tense. Your breathing changes. You might feel shaky, dizzy or sick.

And then there's the particularly annoying bit: you might find it really difficult to think clearly, which isn't ideal when the thing you're anxious about happens to be an exam, an interview or a presentation.

But again, your brain isn't malfunctioning. If Dave is being chased by a tiger, I don't particularly want his brain using valuable resources to contemplate the meaning of life. I want it concentrating on RUN.

The difficulty is that you can't run away from ‘What if I fail?’

And then anxiety plays another trick on us

Remember what happened to Dave's attention when he heard the twig snap? He started looking for the tiger. And we do exactly the same thing.

If you're frightened you're going to make a fool of yourself during a presentation, you'll probably notice every word you stumble over, every awkward pause and every slightly ambiguous expression on somebody's face.

If you're worried about your health, you'll probably start noticing sensations in your body that you'd normally pay absolutely no attention to.

And if you're already worried that something bad is about to happen, guess what your brain starts looking for? Yep. Signs that something bad is about to happen.

So now you have a thought that something might be wrong, your threat system responds to it, your body starts producing very real physical sensations, and your attention starts looking for more evidence of danger.

No wonder anxiety feels so convincing.

So, what do we do about it?

One of the first things I want people to understand about anxiety is that your brain isn't trying to make your life miserable. Quite the opposite. It's trying to keep you safe. It's just sometimes a little overenthusiastic about it.

And this is where CBT becomes really useful. We can start looking at your own version of Dave's sabre-toothed tiger. What has your brain learned to see as threatening? What sets off your alarm system? What happens in your body when it does? And what do you do next?

Because sometimes the things we do to make ourselves feel safer in the short term actually convince our brain that there really was something dangerous to begin with - and that's how the cycle of anxiety can keep going.

The aim of CBT isn't to get rid of anxiety. I wouldn't want to.

If you walk out of your house tomorrow morning and there is an actual sabre-toothed tiger (or a baddie, etc) standing on your driveway, please feel free to panic.

The aim is to help your brain get better at working out which threats need the full Dave-the-caveman emergency response and which ones don't.

And that takes time. When your brain has learned that something is dangerous, the fear you feel is very real — even when the danger it is warning you about isn't. CBT isn't about telling you that you're worrying over nothing. It's about helping your brain learn, gradually and through experience, that it doesn't always need to sound the alarm.

Because sometimes a snapped twig really is just a snapped twig.