What is the fight-or-flight response?

December 24, 2025

Lawrie

In brief

  • The fight or flight response is a normal bodily response to perceived danger
  • Strong physical and psychological symptoms can be triggered by a fear of flying
  • There are practical things you can do to reduce and manage the impact of the fight and flight response

Fight or flight explained – and why it shows up when you fly

The fight or flight response is an ancient survival mechanism prepares our bodies to face a threat or escape it. Turbulence, engine noises, sitting at the gate, or even booking a flight can trigger intense reactions that feel out of proportion to the situation.

Understanding fight or flight is the first step to managing it. We’ll explain what the fight or flight response is, how it’s activated in anxious flyers and provide some practical ways you can deal with it.

Person sat alone by a lake

The origins of fight or flight

The term “fight or flight” was first popularised by American physiologist Walter Cannon in the early 20th century. He described how animals – including humans – respond to threats with a burst of physiological arousal that prepares them either to stand their ground (fight) or flee (flight). 

From an evolutionary perspective, this response helped our ancestors survive encounters with predators or enemies. The surge of energy increased chances of survival.

Today, however, our brains still trigger the same reaction in non-lethal situations – from work stress to air travel.

How the fight or flight response works

The response is controlled by the sympathetic nervous system, a branch of the autonomic nervous system that regulates involuntary functions. When the brain perceives a threat, the amygdala signals the hypothalamus, which activates the adrenal glands.

These glands release hormones such as:

  • Adrenaline (epinephrine): increases heart rate, blood pressure, and breathing rate.
  • Cortisol: mobilises glucose for energy and suppresses non-essential systems (like digestion).

The result is a cascade of changes preparing the body for action. 

Symptoms of fight or flight

The response feels different for everyone, but common physical signs of the fight or flight response include:

  • Racing heart or palpitations
  • Sweating
  • Shaking or trembling
  • Dry mouth
  • Shortness of breath
  • Nausea or “butterflies” in the stomach
  • Muscle tension
  • Feeling lightheaded

Psychological symptoms include:

  • Heightened alertness (“hypervigilance”)
  • Intrusive “what if” thoughts
  • Difficulty concentrating
  • A sense of doom

For nervous flyers, these symptoms often start before boarding and peak during turbulence or takeoff. 

Why it’s triggered in modern life

The fight or flight response is automatic and part of what makes us human beings. 

The mind doesn’t distinguish between the danger of a sabre-toothed tiger and a safe but stressful modern trigger like public speaking, exams, or stepping on board a plane.

Anxiety can have many different triggers for fearful flyers. Some common causes for anxiety include turbulence, engine noises, claustrophobia and anticipation. Some people who are comfortable flying alone find that flying with children can trigger anxiety for the first time.

Whatever the cause or trigger of your anxiety, the psychological and physical feelings are very real – but they’re also temporary. 

People of the inside of a plane and the plastic moulding

What this means for nervous flyers

Fear of flying is often described as “irrational.” But when you see it as an exaggerated fight or flight response, it makes sense. Your body is doing its job, it’s just misreading the situation you’re in. Flying is safe, but your mind doesn’t perceive it as such.

By learning strategies to calm the nervous system, you can reduce the intensity of fight or flight during a flight. With practice, these techniques become second nature.

Flying will never trigger zero stress, but the goal is to bring it back into proportion.

How to cope with the fight or flight response

Understanding the biology, symptoms, and psychology behind it can be empowering. With the right tools (like breathing, grounding, mindfulness, and CBT) you can effectively retrain your response. In time, flying can become less about panic and more about perspective.

For a little extra support, you can download our Calm Flight Toolkit or visit our Help Desk.

If you find yourself struggling on a plane, remember: it’s not danger, it’s fight or flight – and you can calm it.

Please share this article with anyone who might benefit from it.

FAQs

What is the fight-or-flight response?

The fight-or-flight response is a normal bodily response to perceived danger. The body prepares to either face the danger and fight it, or gain the strength to escape. The physical symptoms like an increased heart rate and shallow breathing are accompanies by psychological ones.

Why does fear of flying activate the fight-or-flight response?

Flying – or for some, even the thought of flying – can trigger anxiety automatically because our brains associate flying with something that’s dangerous. We know that flying is safe, but our brains aren’t rational, they simply react.

How can I deal with the fight-or-flight response?

If your’e experience acute anxiety, then breathing and grounding exercises can help bring you back to the present – and avoid you entering into an anxiety spiral, which can result in a panic attack. In the long-term, understanding aviation, exposure therapy and professional support can all help you to establish a healthy relationship with flying that’s rational and based on risk.

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