Episodic paroxysmal anxiety is the clinical name for panic disorder. The term was used in the ICD-10 (the international system for classifying diseases) under code F41.0, describing a condition where sudden, intense surges of fear strike without warning and then recede. When the ICD-11 replaced the older system, the label “episodic paroxysmal anxiety” was dropped in favor of simply “panic disorder” to align with the terminology used in the DSM-5. The two names describe the same condition.
The name itself is descriptive: “episodic” means it comes and goes, “paroxysmal” means the onset is sudden and intense, and “anxiety” refers to the core experience. If you’ve come across this term on a medical record or diagnostic code, you’re looking at panic disorder.
What a Panic Episode Feels Like
A panic attack typically peaks within about 10 minutes and lasts anywhere from 5 to 20 minutes total, though some people report episodes stretching up to an hour. The physical symptoms are intense enough that many people believe they’re having a heart attack the first time it happens. Common symptoms during an episode include a pounding or racing heart, sweating, trembling, chest pain, difficulty breathing, dizziness or weakness, tingling or numbness in the hands, stomach pain, nausea, and chills.
Beyond the physical experience, panic attacks produce a distinct psychological state: a feeling of being completely out of control, sometimes accompanied by a fear of dying or a sense of impending doom. These cognitive symptoms are what separate a panic attack from, say, simply being winded after exercise or having a racing heart from too much caffeine. The combination of intense physical sensations and overwhelming dread is the hallmark of the condition.
What turns isolated panic attacks into panic disorder is the pattern. People with this condition experience repeated, unexpected attacks and often develop a persistent fear of the next one. That anticipatory anxiety can become its own burden, leading people to avoid situations where they’ve previously had attacks or where they feel escape would be difficult.
What Happens in the Brain During an Episode
Panic attacks originate in the brain’s emotional processing centers rather than its higher reasoning areas. The amygdala, a small structure deep in the brain that evolved to detect threats and trigger survival responses, plays a central role. During a spontaneous panic attack, brain imaging has shown significantly increased activity in the right amygdala.
When the amygdala fires, it activates the body’s stress response system. A chain of hormonal signals releases stress hormones, which produce the racing heart, rapid breathing, and muscle tension you feel during an attack. Normally, other brain regions act as a brake on this system, calming things down when there’s no real threat. In people with panic disorder, that braking system appears to work less effectively. Studies have found that during panic, activity in the prefrontal cortex (the brain’s rational, planning center) decreases while the amygdala and surrounding emotional circuits ramp up.
At the chemical level, the balance between calming and excitatory brain signals seems disrupted. Elevated levels of excitatory signaling are associated with panic, which is why medications that calm that activity can help. Norepinephrine, the brain’s version of adrenaline, also runs high during episodes, driving the cardiovascular symptoms that feel so alarming.
Conditions That Mimic Panic Attacks
Because the symptoms of a panic attack overlap with several medical conditions, getting an accurate diagnosis matters. Palpitations can be caused by heart rhythm abnormalities. Difficulty breathing can stem from asthma. Chest pain, dizziness, and sweating can point to cardiac problems or blood pressure issues. Thyroid disorders, particularly an overactive thyroid, can produce anxiety, a racing heart, and trembling that look nearly identical to panic attacks.
This is why a first episode of severe, unexplained panic-like symptoms typically warrants a medical workup. Once physical causes are ruled out, the diagnosis of panic disorder becomes much more straightforward.
How Panic Disorder Is Treated
Cognitive Behavioral Therapy
Structured cognitive behavioral therapy (CBT) is one of the most effective treatments for panic disorder. A typical course runs about 11 sessions and focuses on identifying the thought patterns that fuel panic, gradually exposing you to feared sensations in a controlled way, and teaching you to reinterpret the body’s alarm signals as uncomfortable but not dangerous.
CBT works even when panic disorder occurs alongside other conditions. In one clinical trial of 256 participants, nearly half had at least one additional diagnosis (such as generalized anxiety, depression, or social anxiety) at the start of treatment. Those comorbid conditions did not reduce the effectiveness of CBT for panic. By the end of treatment, the rate of comorbid diagnoses dropped significantly, from about 46% to 31%, suggesting the benefits extended beyond panic symptoms alone.
Medication
When medication is appropriate, SSRIs and SNRIs (antidepressants that also treat anxiety) are the first-line choice. Several have specific FDA approval for panic disorder, including sertraline, fluoxetine, paroxetine, and venlafaxine. These medications are typically started at a low dose and gradually increased, because people with panic disorder can be sensitive to the initial side effects of antidepressants, which sometimes temporarily increase anxiety before the calming effects take hold. It generally takes several weeks for these medications to reach full effectiveness.
The choice between therapy, medication, or both depends on the severity of symptoms, personal preference, and how much the condition is interfering with daily life. Many people do well with CBT alone. Others benefit from combining it with medication, particularly if attacks are frequent or severe enough to prevent engagement with therapy.
Coping During an Active Episode
When a panic attack hits, the most effective immediate strategy is to slow your breathing. Taking slow, deep breaths counteracts the hyperventilation that intensifies symptoms like dizziness, tingling, and chest tightness. Breathing in for a count of four, holding briefly, and exhaling for a count of six gives your nervous system a direct signal to stand down.
Grounding techniques can also interrupt the spiral. The 5-4-3-2-1 method works by pulling your attention out of your body and into your surroundings: notice five things you can see, four things you can touch, three things you can hear, two things you can smell, and one thing you can taste. This isn’t a cure, but it forces the brain to engage its sensory processing systems, which competes with the amygdala-driven fear response. Over time, using these techniques consistently during episodes can reduce their intensity and shorten their duration.
Reminding yourself that the attack will pass, typically within 10 to 20 minutes, is itself a powerful intervention. Much of the terror of a panic attack comes from the belief that the symptoms are escalating toward something catastrophic. Knowing the timeline helps break that belief.
How Common It Is
Anxiety disorders are widespread. CDC data from 2022 found that about 18% of U.S. adults experienced anxiety symptoms in the prior two weeks, with roughly 3.9% reporting moderate symptoms and 2.8% reporting severe symptoms. Panic disorder specifically affects an estimated 2 to 3% of the population in any given year, making it one of the more common anxiety disorders. It tends to emerge in late adolescence or early adulthood, and women are diagnosed roughly twice as often as men.