Anxiety Disorders — Types, Causes, Symptoms & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Anxiety disorders are a group of mental health conditions characterised by excessive, persistent, and disproportionate fear, worry, and apprehension that cause significant distress or impairment in daily functioning. They are the most common mental health conditions worldwide — affecting 301 million people (4% of the global population) — and are the leading cause of global disability from mental illness. The main types, classified by DSM-5 and ICD-11, include: Generalised Anxiety Disorder (GAD — chronic, pervasive worry about multiple topics lasting more than 6 months, with associated somatic symptoms including muscle tension, fatigue, and sleep disturbance); Panic Disorder (recurrent unexpected panic attacks with anticipatory anxiety and agoraphobic avoidance); Social Anxiety Disorder (intense and persistent fear of social or performance situations causing significant avoidance — affecting approximately 7% of adults); Specific Phobias (situational, animal, blood-injection-injury, natural environment subtypes); Agoraphobia (fear of and avoidance of situations from which escape might be difficult); and Separation Anxiety Disorder (now recognised in adults as well as children). Anxiety disorders frequently co-occur with depression (in 50-60% of cases), substance use disorders, and chronic physical health conditions. Despite being among the most treatable mental health conditions — with evidence-based therapies achieving 60-80% response rates — less than 25% of affected individuals globally receive any treatment, due to stigma, lack of awareness, and healthcare access barriers.

Anxiety disorders result from a complex interaction of genetic, neurobiological, psychological, and environmental factors. Genetics: heritability is approximately 30-40%; having a first-degree relative with an anxiety disorder increases risk 4-6-fold; specific genetic variants in serotonin transporter (SLC6A4), COMT, and GABA receptor genes contribute. Neurobiological mechanisms: the amygdala (threat detection centre) is hyperactive in anxiety disorders — excessive fear conditioning and insufficient extinction from the prefrontal cortex creates an inability to 'turn off' the fear response; dysregulation of serotonin, noradrenaline, GABA, and glutamate neurotransmitter systems underpins the pharmacological targets of treatment; the HPA (hypothalamic-pituitary-adrenal) axis is dysregulated, producing excess cortisol in response to perceived threats. Psychological risk factors: adverse childhood experiences (ACEs) including abuse, neglect, and early trauma significantly increase lifetime anxiety disorder risk; behavioural inhibition (temperamental shyness in childhood); perfectionism, low self-efficacy, and negative cognitive bias (catastrophic thinking patterns). Environmental triggers: chronic stress (financial, occupational, relationship); major life events (bereavement, relationship breakdown, job loss); physical illness (thyroid disease, cardiac arrhythmias, asthma, chronic pain); caffeine and alcohol (both acutely trigger and chronically worsen anxiety); cannabis use (psychotic anxiety); corticosteroids, sympathomimetics, and thyroid hormone excess as medication causes.

Anxiety disorders produce both psychological and physical symptoms that vary by type and severity. Core psychological symptoms include: excessive, uncontrollable worry about multiple domains (GAD); intense apprehension and dread; restlessness and an 'on edge' feeling; irritability; difficulty concentrating ('mind going blank'); and pervasive sense of impending catastrophe. Physical symptoms arise from chronic autonomic nervous system activation (sympathetic 'fight-or-flight' response): muscle tension and aches (particularly neck, shoulders, and jaw); headaches (tension-type); fatigue; sleep disturbance (difficulty falling asleep or staying asleep — affects 85% of GAD patients); rapid or pounding heartbeat (palpitations); shortness of breath; dry mouth; nausea, abdominal cramps, and irritable bowel symptoms; sweating and trembling; and dizziness or lightheadedness. Panic attacks — the hallmark of Panic Disorder but occurring in other anxiety disorders — are discrete episodes of sudden intense fear with palpitations or pounding heart, sweating, trembling, shortness of breath, chest pain or tightness, nausea, dizziness, derealisation (feeling unreal), paraesthesia (numbness or tingling), and fear of dying or 'going crazy' — peaking within 10 minutes and causing post-attack anticipatory anxiety. Social anxiety disorder produces marked distress and avoidance of social interactions, public speaking, eating in public, and performance situations — leading to profound occupational and relationship impairment. Specific phobias cause intense immediate fear reactions to specific objects or situations (blood-injection-injury phobia can cause vasovagal syncope — fainting).

Diagnosis is clinical — based on DSM-5 (Diagnostic and Statistical Manual, 5th Edition) or ICD-11 criteria applied through a structured or semi-structured clinical interview. Key diagnostic criteria for GAD require excessive anxiety and worry about multiple events or activities on more days than not for at least 6 months, associated with at least three of six symptoms (restlessness, fatigue, concentration difficulties, irritability, muscle tension, or sleep disturbance), causing significant distress or functional impairment, not explained by substances or medical causes. Validated screening and monitoring tools include: GAD-7 (7-item scale; scores 5-9: mild, 10-14: moderate, 15-21: severe anxiety — widely used in primary care); Patient Health Questionnaire-9 (PHQ-9) to assess comorbid depression; Hamilton Anxiety Rating Scale (HAM-A) for clinical and research severity quantification; Social Phobia Inventory (SPIN) for social anxiety; Panic Disorder Severity Scale (PDSS). Medical exclusion is essential before diagnosing a primary anxiety disorder — organic causes that mimic anxiety: hyperthyroidism (TFTs), phaeochromocytoma (plasma or urine metanephrines if suspected), hypoglycaemia (fasting glucose), cardiac arrhythmias (ECG for palpitations), anaemia (FBC), and medication effects (stimulants, corticosteroids, bronchodilators, thyroid supplements, caffeine). Substance use assessment (alcohol, cannabis, stimulants) is integral. Comorbidity assessment — anxiety disorders co-occur with depression (50-60%), other anxiety disorders (often more than one), personality disorders, PTSD, OCD, and chronic physical illness — and co-occurring conditions must be addressed simultaneously.

Treatment of anxiety disorders combines psychological therapy and pharmacotherapy for moderate-to-severe presentations, with psychological therapy preferred as first-line for mild-moderate anxiety. Psychological therapies: Cognitive Behavioural Therapy (CBT) is the gold-standard evidence-based treatment — typically delivered in 12-20 weekly sessions; it targets dysfunctional thought patterns (cognitive restructuring) and behaviour (exposure and response prevention); response rates are 60-80% across anxiety disorder types. Exposure therapy (a core CBT component) is central to treating specific phobias, OCD, PTSD, panic disorder, and social anxiety — involving systematic gradual confrontation of feared situations or stimuli. Acceptance and Commitment Therapy (ACT) and Mindfulness-Based Cognitive Therapy (MBCT) are evidence-based alternatives or adjuncts with comparable efficacy. Pharmacotherapy: SSRIs are first-line for all major anxiety disorders — sertraline 50-200 mg/day, escitalopram 10-20 mg/day, paroxetine 20-60 mg/day (note: start low to avoid initial anxiety exacerbation); full therapeutic benefit takes 4-6 weeks, and 8-12 weeks of treatment is needed before judging response. SNRIs (venlafaxine XR 75-225 mg/day, duloxetine 60-120 mg/day) have comparable efficacy and are particularly effective for GAD and social anxiety disorder. Pregabalin (150-600 mg/day) is licensed for GAD — provides faster onset than SSRIs, useful for patients who cannot wait for SSRI effect. Buspirone (15-60 mg/day — divided doses) is a non-addictive anxiolytic for GAD with a 2-4 week onset. Beta-blockers (propranolol 10-40 mg PRN) help with situational performance anxiety and physical symptoms. Benzodiazepines (diazepam, lorazepam): provide rapid symptom relief but are not recommended for regular use beyond 2-4 weeks due to significant dependence, tolerance, and cognitive impairment risks — appropriate only for short-term crisis management. Treatment duration: a minimum of 6-12 months of pharmacotherapy after achieving response before attempting discontinuation; relapse risk is high after short courses. Combined CBT plus pharmacotherapy is superior to either alone for moderate-severe anxiety.

Untreated anxiety disorders significantly impair occupational functioning (absenteeism, reduced productivity, job loss), academic performance, and social relationships. Chronic anxiety increases risk of comorbid major depressive disorder — which co-occurs in 50-60% of cases — creating a bidirectional reinforcing cycle that worsens prognosis and treatment response. Substance misuse disorders develop in 30-40% of patients who self-medicate with alcohol, cannabis, or benzodiazepines, ultimately worsening anxiety through neuroadaptation and withdrawal. Physical health consequences from chronic HPA axis hyperactivation include increased cardiovascular risk (anxiety doubles MI risk), sustained hypertension, immunosuppression, irritable bowel syndrome, chronic pain syndromes, tension headaches, and insomnia. Severe social anxiety disorder causes avoidance of employment, education, and social contact, leading to isolation and housebound disability; agoraphobia similarly confines patients to home environments, requiring intensive psychological and pharmacological intervention. Anxiety disorders account for significant indirect economic costs through lost productivity — estimated at over $1 trillion annually in lost productivity globally. Early, evidence-based treatment with CBT and appropriate pharmacotherapy prevents chronicity, reduces healthcare utilisation, and improves long-term functional recovery.

Regular aerobic exercise (150 minutes/week) significantly reduces anxiety symptoms through endorphin release and HPA axis regulation. Limit caffeine and alcohol — both worsen anxiety. Practise mindfulness, progressive muscle relaxation, or breathing exercises (4-7-8 breathing, diaphragmatic breathing) daily. Maintain regular sleep hygiene: consistent sleep schedule, no screens before bed, cool dark bedroom. Build social connections and a strong support network. Cognitive restructuring — challenging catastrophic thoughts — is a powerful self-help tool. Seek help early; anxiety disorders respond well to early intervention.

Consult your GP if anxiety is persistent for more than 2 weeks, significantly interfering with daily work, relationships, or sleep, or if it is causing you to avoid activities you previously enjoyed. Seek urgent same-day medical help if you are experiencing thoughts of self-harm or suicide — contact your GP, call 111, or go to A&E. Go to A&E or call 999 if you have severe chest pain or palpitations you cannot attribute to anxiety — to exclude a cardiac cause. Young people under 18 with anxiety symptoms should be referred to their GP or school counselling service promptly, as early intervention is particularly effective. If you are already in treatment and experiencing a relapse, or your symptoms are worsening despite medication and therapy, contact your mental health team or GP for a medication review or additional CBT sessions. In an acute panic attack — breathing slowly, grounding techniques, and reassurance that you are not dying are helpful; if panic attacks are recurring without a clear cause, formal assessment for panic disorder is warranted.