Anxiety is an emotional and physiological state characterised by apprehension, worry, tension or fear associated particularly with anticipated or uncertain threat. Fear is often directed towards an immediate or identifiable danger, whereas anxiety commonly concerns future, uncertain or hypothetical threats, although the distinction is not absolute. Anxiety can be a normal adaptive response that promotes preparation and caution. It becomes clinically significant when it is excessive relative to circumstances, persistent, difficult to control or associated with substantial distress or impairment. Anxiety therefore exists on a continuum from ordinary transient experiences to diagnosable anxiety disorders.
The physiological features of Anxiety can include increased heart rate, muscle tension, sweating, gastrointestinal sensations, rapid breathing and heightened alertness. These responses reflect activation of systems involved in threat detection and preparation for action. Cognitive features can include worry, threat anticipation, uncertainty intolerance, increased monitoring for danger and difficulty disengaging attention from perceived threats. Behavioural responses may include avoidance, reassurance seeking, checking or escape. These responses can reduce anxiety temporarily while sometimes maintaining it over time if they prevent new learning that a feared situation can be tolerated or is less dangerous than anticipated.
Anxiety disorders comprise several distinct clinical patterns rather than one single condition. Generalised anxiety involves excessive and persistent worry across multiple areas of life, while panic disorder involves recurrent unexpected panic attacks together with persistent concern or behavioural changes related to them. Phobic disorders involve marked fear associated with particular situations or objects, and social anxiety disorder centres on fear of scrutiny or negative evaluation in social or performance contexts. Obsessive-compulsive disorder and post-traumatic stress disorder involve prominent anxiety-related processes but have distinct diagnostic characteristics and are classified separately in major diagnostic systems.
Anxiety is influenced by interactions among biological vulnerability, learning, cognition, environmental stressors and social experience. Genetic factors contribute to susceptibility, but they do not determine an individual's outcome. Conditioning can cause previously neutral situations to become associated with threat, while avoidance can reinforce fear by preventing corrective experiences. Cognitive processes such as catastrophic interpretation and overestimation of threat can also contribute. These mechanisms help explain why anxiety can persist even when a person intellectually recognises that a feared outcome is unlikely.
Anxiety and Stress are closely related but not identical. Stress commonly follows demands or circumstances that require adaptation, whereas anxiety can persist without an immediate external stressor and can focus on anticipated threats. Stress can trigger anxiety, and anxiety can increase perceived stress by causing ordinary uncertainties to be interpreted as threatening. Temporary anxiety is not necessarily a disorder. Clinical significance depends on factors including persistence, intensity, controllability, avoidance, distress and interference with work, education, relationships or ordinary activities.
Anxiety can produce avoidance that reduces short-term discomfort but may restrict a person's life over time. For example, someone who fears public speaking may repeatedly avoid presentations and experience immediate relief, but the avoidance can prevent opportunities to learn that anxiety is tolerable and that catastrophic outcomes are less likely than anticipated. Evidence-based psychological treatments can target these maintaining mechanisms. Cognitive behavioural approaches may involve identifying unhelpful interpretations, changing behavioural patterns and gradually confronting feared situations in a structured way when appropriate.
Assessment of Anxiety requires more than identifying whether someone occasionally feels nervous. Clinicians consider the nature of symptoms, duration, triggers, physical manifestations, cognitive patterns, avoidance, functional impairment and possible alternative explanations. Some medical conditions, medications and substances can produce anxiety-like symptoms, so physical factors may need consideration. Screening questionnaires can support assessment but do not independently establish a diagnosis. Severe or rapidly changing symptoms, particularly when accompanied by other concerning physical or psychological signs, warrant appropriate professional evaluation.
Anxiety can often be managed through psychological interventions, lifestyle measures and, when clinically appropriate, medication. Evidence-based psychological therapies can teach skills for changing avoidance, threat interpretations and behavioural responses. Regular sleep, physical activity, stable routines and reduced use of substances that exacerbate anxiety can support overall functioning, although these measures are not universal replacements for treatment. Anxiety should not be treated as a personal weakness or eliminated at all costs, because an appropriate level of caution is adaptive. The relevant distinction is between proportionate anxiety that supports preparation and persistent or excessive anxiety that restricts functioning or causes significant distress.
