What Causes Panic Attacks? The Nervous System Explanation

Maria Niitepold
Nov 19, 2025
15 min read

Updated: Jul 11

By Dr. Maria Niitepold, PsyD | Licensed Psychologist | EMDR, Brainspotting & CRM

Minimalist illustration of a person experiencing a panic response in a calm room, with tight spirals and alert shapes around the body representing nervous system activation.

Something I notice consistently in people who come to me after their first panic attack, or their fiftieth, is a particular quality of bewilderment.

It is not just the fear of having another one. It is something more specific: confusion about why it happened at all. "I was just sitting at my desk." "I was driving on a perfectly normal road." "Nothing was wrong. And then suddenly everything was wrong."

The randomness is one of the most distressing features of panic attacks. So I want to offer something that tends to shift that distress. Panic attacks are not random. They are not signs of weakness, or instability, or a mind that has turned against you. They are the output of a nervous system that has been pushed past its threshold. And the combination of factors behind that, once you can see them clearly, becomes far less mysterious and far more workable.

This post is a clinical explanation of what causes panic attacks, how the nervous system produces them, and what actually changes them. If you have been living with panic and trying to understand it, this is the post to read carefully.

Quick Answer: What Causes Panic Attacks?

Panic attacks are caused by the nervous system's threat response firing at a threshold that doesn't match the actual danger present. Contributing factors usually include nervous system sensitivity, unresolved trauma, cortisol dysregulation, sleep deprivation, hormonal shifts, and stimulants. Most panic attacks involve several factors at once, which is why single-cause explanations rarely fit.

What a Panic Attack Actually Is
The Nervous System Roots: Why Some People Are More Vulnerable
Trauma and Unresolved Threat Responses
Cortisol Dysregulation: The Most Overlooked Cause
Physiological Triggers: Sleep, Hormones, Stimulants, and Illness
Psychological and Relational Triggers
What to Do During a Panic Attack: Somatic Tools That Actually Work
How Therapy Changes Panic: EMDR, Brainspotting, and Somatic Approaches
Checklist: Recognizing Your Panic Pattern

What a Panic Attack Actually Is

A panic attack is a sudden, intense surge of fear with physical symptoms that peaks within minutes and then subsides. Those symptoms include a racing heart, difficulty breathing, chest tightness, dizziness, tingling, a sense of unreality, or a feeling that something catastrophic is about to happen.

The clinical definition is useful. What is more useful for most people is understanding what is actually happening in the body.

A panic attack is the nervous system's threat response firing at full intensity without a corresponding external threat. The amygdala, the brain's alarm system, has decided that danger is present. So it activates the full sympathetic survival response. Adrenaline floods the body, heart rate accelerates, breathing changes, muscles tense, and blood is redirected toward movement. Every one of these changes is adaptive in a genuine emergency. In a panic attack, they occur in the absence of one.

The result is a body in full emergency mode with no emergency to address. That is both physically overwhelming and deeply disorienting.

Panic attacks are not signs of weakness. They are not a mental breakdown. They are what happens when the nervous system's alarm has become sensitive enough to fire at a threshold that does not reflect the actual level of threat. The reasons it became that sensitive are usually identifiable and addressable.

Understanding what causes panic attacks, at the level of the nervous system, is the beginning of being able to change them.

The Nervous System Roots: Why Some People Are More Vulnerable

Not everyone who experiences stress, poor sleep, or significant life pressure develops panic attacks. Understanding why means looking at what sets the nervous system's baseline sensitivity.

Genetics and nervous system inheritance. Some people inherit a more sensitive nervous system: a lower threshold for the amygdala to fire, a more reactive stress response, a stronger pull toward interoceptive awareness (the felt sense of internal bodily states). This is not a flaw. A more sensitive nervous system is often a more perceptive one. But it does mean the threshold for overwhelm is lower, and that matters when other factors stack up.
A narrow window of tolerance. The window of tolerance is the zone of nervous system arousal in which a person can function, feel, and regulate well. When chronic stress, unresolved trauma, or inadequate early co-regulation has narrowed that window, the system has very little buffer before it tips into a survival state. Panic is often the expression of a system pushed outside a window that was already narrow. As I cover in why high-achievers are always anxious or exhausted, this narrowing is extremely common in high-pressure adults. And what expands the window, and how long it takes, is the process that directly reduces panic over time.
Interoceptive sensitivity. People vary in how intensely they feel internal sensations. For someone with high interoceptive sensitivity, a slight rise in heart rate, a subtle change in breathing, or mild dizziness that others would not notice can register as alarming. If the nervous system then reads those sensations as danger, the fear response can escalate fast into a full panic attack. This is not hypochondria. It is a nervous system doing its job with a calibration problem.

Trauma and Unresolved Threat Responses

One of the most significant and most frequently missed causes of panic attacks is unresolved trauma. Particularly trauma that involved helplessness, loss of control, or a threat the nervous system could not fully process at the time.

When a traumatic experience is not fully integrated, the nervous system stores it as an active file rather than a historical one. The amygdala keeps a heightened readiness to respond to anything that resembles the original threat: a tone of voice, a physical sensation, a sensory detail. This happens even when the resemblance is too subtle for the conscious mind to register.

Panic attacks that seem to come out of nowhere usually have a trigger operating below conscious awareness. The subcortical nervous system recognized something as threat-adjacent before the thinking mind had time to evaluate it. The panic is not random. The trigger is simply operating at a level that language cannot easily reach. As I cover in the neuroscience of trauma triggers, this is the same mechanism that produces seemingly disproportionate reactions in everyday situations. The trigger fires before insight can intervene.

This is one reason talk therapy often produces limited results for trauma-related panic. As I explore in why just talking isn't curing your anxiety, reaching the subcortical level where the trigger is stored requires a different kind of intervention.

Trauma-related panic also shows up in the context of attachment. For people with histories of emotional neglect, abandonment, or early relational unpredictability, panic can surface in moments of disconnection, relational conflict, or the anticipation of loss. Those experiences activate the same deep survival wiring that genuine threat activates. The nervous system does not clearly distinguish between physical danger and the loss of essential attachment. Both register as emergency.

On the Gulf Coast, hurricane season is one of the most common hidden triggers I see, and I write about it in EMDR for hurricane trauma.

Cortisol Dysregulation: The Most Overlooked Cause

Cortisol is the body's primary stress hormone. It regulates energy, stabilizes blood sugar, manages the inflammatory response, and sets the arousal level of the nervous system. When cortisol works well, it provides a stable physiological foundation. When it dysregulates, in either direction, the conditions for panic become much more favorable.

High cortisol occurs with chronic stress, overwork, inadequate recovery, and sustained sympathetic activation. It amplifies heart rate, increases muscle tension, heightens sensory awareness, and keeps the nervous system vigilant. These changes closely mimic the early stages of a panic attack. When the system is already in this state, a relatively small additional stressor can be enough to tip it into full panic.

Low cortisol is counterintuitive but equally important. Chronic stress and trauma do not always produce high cortisol indefinitely. Over time, the HPA axis (the hormonal system that regulates cortisol) can dysregulate, producing inadequate cortisol at key points in the day. Low cortisol impairs blood sugar regulation and destabilizes the body's arousal system. The body compensates by releasing adrenaline. That produces jitteriness, a sense of physical unease, and rapid shifts in internal sensation that can cascade into panic, particularly in the morning or between meals.

Many people who experience panic attacks have cortisol dysregulation as a contributing factor that is never assessed. The cortisol piece can explain a lot. Why panic clusters at certain times of day. Why it is worse during periods of poor sleep or irregular eating. Why the body can feel primed for panic even when the psychological situation seems stable. As I explore in how the daily cortisol curve shapes mental health, the cortisol rhythm is one of the most under-leveraged interventions for nervous system regulation, and one of the most directly relevant to panic.

Physiological Triggers: Sleep, Hormones, Stimulants, and Illness

Beyond cortisol, a number of physiological factors lower the threshold for panic by destabilizing the nervous system's baseline regulation.

Sleep deprivation reduces emotional resilience and raises baseline adrenaline. Even a single night of badly disrupted sleep can make internal sensations feel more intense and the fight-or-flight response easier to trigger. For people already vulnerable to panic, poor sleep is one of the most reliable precipitating factors.
Hormonal fluctuations in estrogen, progesterone, testosterone, and thyroid hormones change how the brain processes stress signals. Specific phases, including premenstrual windows, perimenopause, postpartum periods, and thyroid dysfunction, can lower the threshold for panic. Many people first develop panic attacks during a significant hormonal transition and never connect the timing.
Stimulants like caffeine, nicotine, energy drinks, and certain medications activate the cardiovascular system. They can produce sensations the nervous system misreads as early panic signals: a faster heart rate, jitteriness, a slight tremor. For people with high interoceptive sensitivity, that is enough to start a fear response that escalates into full panic.
Medical conditions including cardiac arrhythmias, blood sugar dysregulation, thyroid disorders, vestibular dysfunction, and POTS can produce internal sensations that trigger fear responses, such as palpitations, dizziness, or sudden weakness. When panic attacks are frequent, ruling out relevant medical contributors is an important part of assessment.
Hyperventilation and breath-holding, which many people do involuntarily under stress, alter the balance of oxygen and carbon dioxide in the blood. The resulting dizziness, tingling, chest pressure, and sense of unreality can be frightening enough to start a panic attack in anyone, and they are especially powerful in a sensitized nervous system.

If you have been trying to understand your panic attacks and nothing has fully explained them, or if you have tried managing them and the pattern keeps returning, the issue may be that the work has not yet reached the level where panic actually originates. I offer EMDR, Brainspotting, and CRM for panic and anxiety, in person at the Gulf Breeze, Florida office and online across New York and Florida and throughout all PsyPact states. Book a free 15-minute consultation to find out whether this kind of work feels right for you. No pressure. No commitment. Just a conversation.

Book a free 15-min consult

Or call or text (850) 696-7218

Psychological and Relational Triggers

Not all panic causes are physiological. Several psychological and relational patterns consistently lower the threshold for panic in ways worth understanding specifically.

Perfectionism and chronic self-pressure hold the body in a state of quiet hypervigilance. The activation is low-level but sustained, and it occupies the nervous system's regulatory capacity. When the system is already carrying that baseline tension, even minor stressors can tip it into panic. The perfectionism is not just a personality trait. It is a physiological load.
Learned associations are one of the most clinically significant causes of recurrent panic. If a panic attack happens in a specific context (a particular store, a certain commute, a social situation), the brain can mark that context as inherently threatening. Later exposure to the same place, or even to sensory cues linked to it, can trigger a conditioned fear response before the person is aware of making the association. This is why avoiding the original panic location rarely prevents future attacks. It often makes them more likely, by reinforcing the assessment that the location is dangerous.
Feeling trapped or unable to escape is a powerful trigger that does not require a prior panic history. Situations that limit movement or perceived access to safety (heavy traffic, long meetings, crowded spaces, MRI machines) can activate the fear response in anyone with a narrow window of tolerance. The nervous system processes the perception of entrapment as a genuine threat signal.
Major life transitions, even positive ones, generate uncertainty, which the nervous system reads as a drop in predictability. The stress response becomes more vigilant when the future feels less settled. This is why panic often clusters around transitions: a new role, a move, a significant relationship change, or any shift that alters the structure of daily life.

What to Do During a Panic Attack: Somatic Tools That Actually Work

Most advice about what to do during a panic attack focuses on cognitive strategies: reminding yourself that you are safe, counting breaths, challenging catastrophic thoughts. These have limited effect during an acute attack, for a straightforward neurobiological reason. The prefrontal cortex, which cognitive strategies rely on, goes significantly offline when the amygdala is fully activated. You cannot reason your way out of a full sympathetic activation.

What works better are somatic interventions. Physical actions that directly signal the nervous system that the threat level is lower than it is currently registering.

Extended exhale breathing. The exhale activates the parasympathetic nervous system. Breathing in for four counts and out for eight sends a direct signal to the vagus nerve that down-regulation is appropriate. The extended exhale is the specific mechanism that activates the body's braking system, not slow breathing in general.
Cold water on the face or wrists. Cold water triggers the mammalian dive reflex, which drops heart rate quickly. This is one of the fastest physiological interventions available for a panic attack in progress.
Grounding through physical sensation. Pressing your feet firmly into the floor, holding a cold object, or rubbing your palms together until you feel warmth all pull the nervous system's attention toward present physical reality. Five-senses grounding (naming what you can see, hear, feel, smell, and taste) does the same thing.
Orienting. Slowly look around the room and deliberately take in the environment: what is where, what is moving, what is stable. This activates the orienting response, which signals the nervous system that the environment has been assessed and no immediate threat is present.

These tools interrupt the panic cycle in the moment. They do not change the underlying nervous system patterning that produced the panic. That requires a different kind of work.

How Therapy Changes Panic: EMDR, Brainspotting, and Somatic Approaches

Panic attacks that recur, particularly those tied to trauma, learned associations, or a significantly narrowed window of tolerance, do not resolve through symptom management alone. Managing symptoms during an attack is useful. Changing the patterns producing the attacks means working at the subcortical level where those patterns are stored. That is the level effective trauma therapy is built to reach.

EMDR therapy for panic attacks targets the specific memories, associations, and threat responses fueling the panic. As I explore in using EMDR for panic attacks and anxiety, it uses bilateral stimulation to process stored threat responses, reducing their charge and recalibrating the amygdala's sensitivity. After EMDR, stimuli that previously triggered panic stop producing the same response, because the underlying file has been processed rather than suppressed.

Brainspotting accesses the subcortical brain through specific eye positions that correlate with stored activation. For panic with unclear origins, where there is no identifiable trigger, or where the trigger runs below conscious awareness, Brainspotting's ability to locate and process implicit threat responses without requiring narrative is particularly valuable.

The Comprehensive Resource Model (CRM) is the approach I use when the panic is severe enough that a client's window of tolerance is too narrow to safely approach difficult material directly. CRM builds internal resources, somatic experiences of safety and steadiness, before any processing begins. As I cover in how CRM makes trauma therapy safe, this is the right starting point when activation is high and the window is narrow. And as I describe in why your body has to feel safe first, the resourcing phase is not preliminary to the work. It is what makes the work safe enough to actually produce change.

The goal of somatic trauma therapy for panic is not to teach you to manage symptoms indefinitely. It is to change what your nervous system predicts, so the alarm stops firing at the wrong threshold and panic attacks become infrequent rather than a recurring feature of your life.

Checklist: Recognizing Your Panic Pattern

Read through these slowly. The more clearly you can identify your pattern, the more targeted the treatment can be.

About your panic attacks:

They seem to come without warning or obvious trigger.
They occur most often at specific times of day, particularly morning or between meals.
They cluster around periods of poor sleep, hormonal changes, or high caffeine intake.
They happen most in specific situations: driving, enclosed spaces, social gatherings, medical settings.
You feel a sense of physical unreality or disconnection during them.
They come with a strong fear that something is physically wrong with you.

About your nervous system history:

You have a history of trauma, emotional neglect, or prolonged high-stress periods.
You grew up in an environment that required sustained vigilance or emotional self-suppression.
You are described by others, or yourself, as highly sensitive or highly perceptive.
Rest and stillness feel more uncomfortable than productive activity.
You find it difficult to fully relax even when objectively nothing is wrong.

About your response to panic:

You have begun avoiding situations where you previously had a panic attack.
Your life has become smaller as a result of managing around the possibility of panic.
You have tried breathing exercises, medication, or talk therapy with limited lasting effect.
You feel that something deeper is driving the panic that has not yet been reached.

Frequently Asked Questions

What actually causes panic attacks?

Panic attacks are caused by the nervous system's threat response activating at a threshold that does not reflect the actual level of danger present. This is typically driven by a combination of factors: nervous system sensitivity, unresolved trauma, cortisol dysregulation, sleep deprivation, hormonal fluctuations, stimulant intake, and learned associations between specific contexts and threat. In most cases, several factors contribute at once, which is why single-factor explanations rarely capture the full picture.

Why do panic attacks happen for no reason?

Panic attacks that seem to occur without an obvious trigger almost always have one. It is simply operating below conscious awareness. The subcortical nervous system recognizes threat-adjacent stimuli before the thinking mind has time to evaluate them. A particular tone of voice, a physical sensation, or a sensory detail associated with a past frightening experience can all start a fear response that the conscious mind experiences as coming from nowhere.

Can trauma cause panic attacks?

Yes. Unresolved trauma is one of the most significant contributors to recurrent panic attacks. When a traumatic experience is not fully integrated, the nervous system keeps a heightened readiness to respond to anything resembling the original threat, even when the resemblance is subtle and below conscious awareness. Panic attacks with unclear triggers are frequently trauma responses operating at the subcortical level, which is why trauma therapy is often the most effective long-term approach.

What is the connection between cortisol and panic attacks?

Cortisol dysregulation in both directions lowers the threshold for panic. High cortisol produces sustained physiological arousal, and low cortisol produces instability and compensatory adrenaline surges. Many people with recurrent panic attacks have cortisol patterns that have never been assessed as a contributing factor. Understanding the cortisol piece can explain why panic clusters at certain times of day and why factors like sleep and nutrition affect panic frequency.

How do I stop a panic attack when it's happening?

The most effective in-the-moment interventions are somatic rather than cognitive. Extended exhale breathing (inhale for four counts, exhale for eight) activates the parasympathetic nervous system. Cold water on the face or wrists triggers the mammalian dive reflex and drops heart rate quickly. Pressing your feet into the floor, holding something cold, or slowly orienting to the room using all five senses all help ground the nervous system in present reality. These work better than cognitive reassurance because they operate at the level of the nervous system, rather than trying to reason with a prefrontal cortex that has partially gone offline.

Is EMDR therapy effective for panic attacks?

Yes. EMDR for panic attacks processes the specific threat responses fueling the panic, the memories, learned associations, and trauma, at the subcortical level. After EMDR processing, the stimuli or internal sensations that previously triggered panic stop producing the same response, because the underlying stored threat has been processed rather than suppressed. EMDR is particularly effective for panic tied to identifiable traumatic events or to specific situational triggers.

What is the difference between a panic attack and an anxiety attack?

The terms are often used interchangeably but have clinical distinctions. A panic attack is a discrete, intense episode that peaks rapidly, typically within ten minutes, with specific physical symptoms, and it often occurs unexpectedly. An anxiety attack is a more gradual buildup of distress in response to an identified stressor. Both involve nervous system activation, but the mechanism and time course are different. Recurrent panic attacks that occur without clear situational triggers may indicate panic disorder, which has specific treatment implications.

Can panic attacks be resolved with therapy?

Recurrent panic attacks can be resolved, not just managed, through the right therapeutic approach. The goal of somatic trauma therapy for panic is to change the underlying nervous system patterning producing the attacks, rather than to provide indefinite symptom management. After effective treatment with EMDR, Brainspotting, or CRM, most clients find that panic attacks become rare or stop occurring altogether, because the source of the dysregulation has been addressed rather than worked around.

Panic Attacks Are Not a Life Sentence

Panic attacks are not a life sentence. They are a nervous system pattern, and nervous system patterns can change.

The modalities I use (EMDR, Brainspotting, and CRM) work at the subcortical level where panic actually originates. Not by managing symptoms, but by changing what the nervous system predicts. I work with clients in person at my Gulf Breeze, Florida office and online across New York, Florida, and all PsyPact states.

Your nervous system learned to sound the alarm at the wrong threshold. With the right work, it can learn a new one.

You can book a free 15-minute consultation whenever you are ready. Or call or text (850) 696-7218.