A panic attack is a sudden episode of intense fear or severe discomfort that reaches a peak rapidly, often within minutes, and may occur unexpectedly or in response to a particular situation. The experience can feel physically overwhelming even when there is no immediate external danger.
Common symptoms include a racing or pounding heart, sweating, trembling or shaking, shortness of breath or a sensation of being unable to breathe properly, choking or throat tightness, chest pain or discomfort, nausea or abdominal distress, dizziness or light-headedness, chills or hot flushes, numbness or tingling, and a feeling of being detached from oneself or one's surroundings. A person may also experience an intense fear of losing control, going crazy, fainting or dying. The combination varies between individuals, and not every symptom occurs during every attack.
The physical symptoms of panic are closely related to activation of the autonomic nervous system, particularly the sympathetic "fight-or-flight" response. When the brain interprets a threat, the body rapidly increases cardiovascular activity, breathing and muscle readiness. Adrenaline and related physiological processes can increase heart rate, sweating and trembling while redirecting resources towards immediate action. Breathing may become faster or deeper, and in some people this contributes to hyperventilation. Excessive ventilation can lower carbon dioxide levels in the blood, producing light-headedness, tingling, visual changes and sensations of unreality. These symptoms can then themselves be interpreted as evidence of danger, potentially intensifying the panic response.
Panic attacks can include prominent cognitive and perceptual symptoms. A person may suddenly think that they are having a heart attack, suffocating, dying, losing control or becoming mentally unwell. Derealisation involves feeling that the external world is unreal, dreamlike or strangely distant, while depersonalisation involves feeling detached from one's own body, thoughts or sense of self. These experiences can be frightening but can occur as part of an intense panic response. Importantly, the presence of panic-like symptoms does not establish that an episode is a panic attack, because several medical conditions and substances can produce similar symptoms.
A panic attack is distinguished from ordinary anxiety partly by its abrupt intensity and rapid escalation. Anxiety commonly develops around an anticipated threat and can persist for hours or longer, whereas a panic attack is typically a discrete surge of intense fear or discomfort. Panic attacks can nevertheless occur during periods of anxiety and can be associated with particular triggers. Some are unexpected, while others are situationally predisposed or situationally bound, such as attacks occurring in crowded spaces, while travelling or when confronting a feared object. The diagnostic significance depends not merely on whether an attack occurs but on its context, recurrence and consequences.
Panic symptoms can overlap substantially with urgent physical conditions. Chest pain, severe breathlessness, fainting, marked palpitations or neurological symptoms should not automatically be assumed to be psychological, particularly when symptoms are new, unusually severe, occur with exertion, or differ from previous episodes. Heart rhythm disturbances, asthma, low blood glucose, thyroid disorders, medication effects, stimulant use and other medical problems can produce symptoms resembling panic. Emergency assessment is appropriate when symptoms suggest a potentially serious acute medical condition. A previous diagnosis of panic disorder does not mean that every future episode of chest pain or breathlessness should be attributed to panic.
Substances can trigger or amplify panic-like symptoms. Caffeine, nicotine, some recreational drugs, certain medicines and withdrawal from alcohol or sedative drugs can affect autonomic arousal and produce sensations such as rapid heartbeat, tremor or anxiety. Sleep deprivation and physical exhaustion can also increase vulnerability. Because these factors can overlap with genuine panic attacks, clinicians usually consider substance use, medication history and physical health when evaluating recurrent episodes. The timing of symptoms relative to substances, illness or medication changes can be particularly informative.
A single panic attack does not necessarily mean that a person has panic disorder. Panic disorder involves recurrent unexpected panic attacks accompanied by persistent concern about additional attacks or their consequences and/or significant maladaptive changes in behaviour related to the attacks. Panic attacks can also occur in other anxiety disorders, post-traumatic stress disorder, depression and certain phobias, or without developing into a psychiatric disorder. Avoidance of places or activities because of fear of panic can become clinically important, especially when it restricts work, education, travel or social functioning.
The experience of panic is highly individual, but its defining feature is the rapid onset of intense fear or discomfort accompanied by multiple physical, cognitive or perceptual symptoms. Recognising the pattern can help a person understand what is happening, but symptom recognition should not be used to rule out physical illness when symptoms are concerning or unfamiliar. Effective assessment considers the episode itself, possible medical and substance-related explanations, previous attacks, triggers, avoidance, functional effects and associated mental-health symptoms.
