Fight, Flight, Freeze: What's Happening in Your Body

Your heart is pounding. Your thoughts are racing. You feel restless, on edge, unable to settle. Or maybe the opposite: you feel foggy, heavy, disconnected, like you're watching your life from behind glass.

These experiences have names. They're your nervous system's survival responses, and they're designed to protect you from danger. Understanding what's happening in your body when these states activate can help you recognize patterns, make sense of symptoms that seem random, and begin to work with your nervous system rather than against it.

Your Nervous System's Job

Your autonomic nervous system runs in the background, managing functions you don't have to think about: heart rate, digestion, breathing, temperature. It also manages your response to threats.

When your brain perceives danger, your nervous system launches a survival response. This happens automatically, without conscious thought, faster than your rational mind can process. The response is designed to keep you alive, and it's remarkably effective at that job.

The challenge is that your nervous system can't distinguish between a genuine threat and a perceived one. A difficult email can trigger the same response as a physical attack. A conflict with your partner can activate the same survival mechanisms as encountering a predator. Your body responds to what it perceives, not to what's objectively true.

Fight: Mobilizing Against the Threat

The fight response is what happens when your nervous system decides the best way to survive is to confront the danger head-on.

When fight activates, your sympathetic nervous system floods your body with adrenaline and cortisol. Your heart rate increases. Blood flows to your large muscles. Your pupils dilate. Your body is preparing for physical combat.

In your body, fight might feel like heat rising, especially in your chest and arms. Tension in your jaw, your fists, your shoulders. A surge of energy that wants to move outward. Restlessness, agitation, a sense of pressure building.

Emotionally, fight often shows up as anger, irritation, frustration, or rage. You may feel defensive, critical, or combative. Small things might set you off. You may find yourself snapping at people, picking arguments, or feeling a pervasive sense of annoyance.

When fight becomes chronic, it can look like persistent irritability, difficulty relaxing, muscle tension that never fully releases, jaw clenching or teeth grinding, high blood pressure, or inflammatory conditions. You may be quick to anger and slow to calm down.

Flight: Escaping the Threat

The flight response is what happens when your nervous system decides the best survival strategy is to get away from the danger.

Like fight, flight activates the sympathetic nervous system. Your body prepares for rapid movement. Heart rate increases, breathing quickens, blood flows to your legs. Your body is getting ready to run.

In your body, flight might feel like restlessness, an inability to sit still, jittery energy in your legs. A sense of wanting to escape, to be anywhere but here. Shallow, rapid breathing. A racing mind that jumps from thought to thought.

Emotionally, flight often shows up as anxiety, worry, or panic. You may feel overwhelmed by ordinary tasks. You might avoid situations, procrastinate, or find yourself constantly busy as a way of outrunning uncomfortable feelings.

When flight becomes chronic, it can look like generalized anxiety, insomnia, an inability to slow down, digestive issues from constantly shallow breathing, or a pattern of avoidance that shrinks your life. You may feel like you're always running but never arriving anywhere.

Freeze: When Neither Works

The freeze response is what happens when your nervous system determines that neither fighting nor fleeing will work. It's a more primitive response, a last resort when the danger is inescapable.

Freeze is a combination of activation and immobilization. Your sympathetic nervous system is still pumping out stress hormones, but your body can't discharge them through action. Instead, you're stuck, like a car with the gas and brake pressed simultaneously.

In your body, freeze might feel like paralysis, being unable to move or speak. Holding your breath. A sense of being stuck or trapped. Numbness, especially in your extremities. Time may seem to slow down or speed up.

Emotionally, freeze often shows up as blankness, disconnection, or a feeling like you're watching through glass. You may feel like you're watching yourself from outside your body. Decision-making becomes impossible. You may dissociate, zone out, or lose track of time.

When freeze becomes chronic, it can look like depression, chronic fatigue, feeling stuck in life, brain fog, or a persistent sense of disconnection from yourself and others. You may feel simultaneously wired and exhausted, unable to rest but also unable to take action.

Shutdown: Beyond Freeze

Sometimes the nervous system goes beyond freeze into complete shutdown. This is the dorsal vagal response, the most primitive survival mechanism we have.

Shutdown is what happens when the system has been overwhelmed to the point of collapse. Energy is conserved by essentially powering down non-essential functions. It's the body's last-ditch effort to survive what it perceives as unsurvivable.

In your body, shutdown feels like heaviness, exhaustion, an inability to move. Low blood pressure, slow heart rate, cold extremities. A sense of emptiness or numbness that goes beyond ordinary fatigue.

Emotionally, shutdown can feel like hopelessness, apathy, or complete disconnection. You may feel nothing at all. Depression, in many cases, is a form of chronic shutdown.

Why You Get Stuck

In an ideal world, these survival responses would activate when needed and resolve when the threat passes. You'd fight or flee, the danger would end, and your body would return to baseline. Animals in the wild do this naturally, shaking off the activation after a predator attack and returning to grazing.

Humans often don't complete this cycle. We suppress our responses because it's not socially acceptable to fight or flee. We tell ourselves to calm down before our bodies have actually calmed. We push through, override, power on.

When survival responses don't complete, the activation stays in your system. Your nervous system remains on alert, waiting for the other shoe to drop. Over time, what was meant to be a temporary state becomes your new normal. You're not responding to a current threat anymore. You're living in a threat state.

This is how people end up chronically anxious, chronically angry, chronically numb. Their nervous systems got stuck somewhere along the way and never found their way back to baseline.

Recognizing Your Patterns

Most people have a default stress response, a pattern they tend to fall into when activated. Understanding yours can help you recognize when you're in a survival state and need support.

Some people are fight-dominant. They get irritable under stress, pick arguments, feel angry for reasons they can't explain. Their bodies run hot, their muscles stay tense, their jaws ache from clenching.

Some people are flight-dominant. They get anxious under stress, can't stop moving or thinking, feel overwhelmed by everything. Their minds race, their sleep suffers, they're always planning their escape.

Some people are freeze-dominant. They shut down under stress, can't make decisions, feel paralyzed when they most need to act. They dissociate, zone out, and lose time.

Many people cycle between states, moving from anxiety to anger to shutdown depending on the situation and how depleted they are. The more overwhelmed the system becomes, the more likely it is to drop into freeze or shutdown.

What This Means for Your Health

When your nervous system is chronically stuck in a survival state, every other system in your body is affected.

Digestion requires parasympathetic activation, the rest and digest state. If you're chronically in fight or flight, digestion suffers. Bloating, constipation, acid reflux, and IBS are common.

Sleep requires your nervous system to feel safe enough to power down. If you're stuck in vigilance, deep sleep becomes impossible. You may sleep for eight hours and wake exhausted.

Hormones are regulated in part by your nervous system. Chronic stress affects your thyroid, your sex hormones, your cortisol rhythms. Fertility, libido, and menstrual regularity all depend on a regulated nervous system.

Immune function is suppressed by chronic stress. You may get sick more often, heal more slowly, or develop autoimmune patterns where your immune system attacks your own tissue.

Your survival responses aren't the problem. They're doing exactly what they evolved to do. The problem is when they don't turn off, when your body keeps responding to threats that have passed or perceiving threats where none exist.

Finding Your Way Back

Regulating your nervous system isn't about forcing yourself to calm down or pushing yourself to take action. It's about creating conditions where your body can actually settle. It's about creating conditions where your body can actually settle.

The first step is recognizing what state you're in. Learning the felt sense of fight, flight, freeze, and shutdown in your own body. Noticing when you've been activated before you're fully overwhelmed.

The second step is completing the stress cycle. Your body needs to discharge the activation that built up. This might mean movement, shaking, breathing, crying, or other ways of letting the energy move through rather than stay stuck.

The third step is building capacity over time. Your nervous system can learn that safety is possible, that activation can resolve, that you won't be stuck forever. This learning happens through repeated experiences of moving from stress into rest, building the neural pathways that allow for flexibility.

Practices like extended exhale breathing, gentle movement, orienting to your environment, and social connection all support this process. Acupuncture directly affects the autonomic nervous system, helping shift your body out of survival states and into rest. For a deeper exploration of practical approaches, see our article on how to regulate your nervous system.

What This Looks Like in Practice

A man came to us at 44, brought in by his wife. She'd been coming for her own work and finally convinced him to try acupuncture for the heart palpitations that had been scaring him and the insomnia that had plagued him for over a year. His cardiologist had cleared him. Nothing was wrong with his heart. But something was clearly wrong.

What his wife wanted to talk about, and what he initially wouldn't, was that they'd been fighting constantly. Their intimacy had disappeared. She felt like she couldn't reach him, like he was always somewhere else even when he was home.

He worked in finance, a highly competitive environment where the pressure never let up. He described his job the way someone describes weather: just how it was. Relentless pace, always on, never a moment without a problem to solve. He ran every morning before the kids woke up. He answered emails during dinner. He couldn't remember the last time he'd done nothing.

He was living in fight and flight. His nervous system had been in survival mode so long he'd forgotten there was any other way to be. The palpitations were his body's alarm system trying to get his attention. The insomnia was a system too wired to settle. The distance his wife felt was real: he wasn't available because he wasn't actually in his body. He was always three steps ahead, managing the next crisis.

We started with weekly acupuncture. He was skeptical but desperate enough to try. The first session, he couldn't stop talking about work. His mind wouldn't let go. Gradually, he started settling. He'd come in activated and leave calmer. He began to notice the difference.

We talked about what fight and flight look like in daily life. He started recognizing it: the urge to check his phone, the inability to sit through a movie, the way he deflected his wife's attempts at connection by finding something that needed doing. He began experimenting with staying instead of escaping. Staying in a conversation. Staying present with his kids. Staying in his body when discomfort arose.

The palpitations decreased. His sleep improved. But what he talked about most was his marriage. As his nervous system learned to settle, he could actually be present with his wife. The fighting decreased because he wasn't so reactive. The intimacy returned because he was finally there.

What had changed wasn't his heart. It was his nervous system. Once he stopped running, he could finally arrive.

Read stories from others who have done this work →

Your Next Step

Learning to recognize your survival responses is the beginning of changing your relationship with them. When you can notice that you're in fight, flight, or freeze, you have more options. You can choose to support yourself rather than push through.

If you've been living in a survival state for years, your nervous system may need help finding its way back to baseline. This is where acupuncture and nervous system work can be particularly effective. We help your body remember what rest feels like.

Contact us at 212.432.1110 or info@fafwellness.com.