One of the most reassuring things I can tell clients is that nothing about their fear is unusual. Their bodies are doing exactly what they were designed to do. In evolutionary terms, the fight, flight, or freeze response kept us alive. The difficulty is that your body cannot distinguish between a real threat and something that simply feels threatening. So it reacts as if your life is in danger, even when you are only standing up to speak.
Let’s take a closer look at what is actually going on.
When your body chooses fight or flight
The moment your brain senses a threat, it sends a message to your adrenal glands. They release adrenalin and cortisol, which activate your sympathetic nervous system. Your body prepares for immediate action long before your rational mind has a chance to catch up.
You might recognise some of these effects:
• Your heart pounds as your body rushes oxygen to your major muscles
• Blood moves away from your hands and feet, creating coldness or tingling
• You breathe more quickly and may feel light-headed
• Your stomach reacts because digestion is no longer a priority
• You blush as blood moves to your head
• Your muscles shake because they are primed for movement
These symptoms can show up in the moments leading up to speaking or continue while you are on your feet.
When your body chooses freeze
Freeze tends to happen while people are actually speaking. It is that moment when someone says, “My mind has gone blank,” or describes feeling disconnected from their own words.
From an evolutionary perspective, freeze was a survival strategy when neither fighting nor fleeing was possible. The body shut down – by ‘playing dead’ a predator was less likely to attack. With public speaking, this shows up as mental fog, disassociation, or a sense of being stuck.
Physiologically, when cortisol overwhelms your system and the sympathetic response cannot keep up, your parasympathetic system steps in. Normally, it supports rest and recovery, but under intense stress, it can create that sensation of shutting down. This explains why people forget their content or feel as if their thoughts have scattered.
The amygdala: your over–protective alarm system
All of this starts with the amygdala, the part of the brain that detects danger before your conscious mind has time to evaluate the situation. It is excellent at spotting threats but not nearly as good at distinguishing between real danger and imagined danger. If you have had a previous embarrassing speaking moment, the amygdala stores that memory and tries to protect you by triggering anxiety long before your next talk.
So what can you do?
I have written extensively about managing nerves, shifting your mindset, and connecting with your audience. Because this article focuses on physiology, here are strategies that help calm the body. They are most effective when combined with mental tools and plenty of low–stakes practice in safe environments.
1. Stimulate your vagus nerve
Slow breathing, cold water, humming, laughing, and even gargling can activate the vagus nerve, which helps calm the body. These are quick and useful if you are experiencing strong fight or flight symptoms before you speak.
2. Experiment with power posing
Amy Cuddy’s well-known TED talk popularised the idea of using expansive body language before speaking. Two minutes of open posture may help reduce stress hormones and increase feelings of power. Some clients find it helpful. Others prefer quieter grounding strategies. It is worth experimenting.
3. Use movement when you speak
Freeze is more likely when you stand rigidly in one spot. Purposeful movement gives your body somewhere to channel adrenalin. You might step toward one side of the room, then the other, or use your hands more deliberately. Movement not only feels more natural, it signals to your nervous system that you are not trapped.
Your body is trying to protect you, not sabotage you
This is the most important thing to understand. Your symptoms are not a sign of weakness or lack of capability. They are the result of a nervous system responding to what it perceives as a threat. With the right tools, practice, and patience, that system can be retrained.
If you want a quick, accessible explanation to share with others, the short Ted Ed animation on stage fright is excellent. And remember: your audience is not the danger your brain thinks it is. Most people want you to succeed.
