## Overview
Anxiety is a normal emotional response characterized by feelings of worry, nervousness, or unease about events with uncertain outcomes. When anxiety becomes persistent, excessive, and disproportionate to actual threats — interfering with daily functioning — it may constitute a clinical anxiety disorder classified under ICD-10 code F41.
Anxiety disorders are among the most prevalent mental health conditions worldwide. According to epidemiological data, approximately 31% of U.S. adults experience an anxiety disorder at some point in their lifetime, with 12-month prevalence rates of roughly 18% [7]. Globally, the World Health Organization estimates that 301 million people were living with an anxiety disorder as of 2019, making it the most common mental health condition.
People search for information about anxiety for many reasons: to understand whether their symptoms are "normal," to identify potential causes, to find evidence-based coping strategies, and to determine when professional help is warranted. This article provides a comprehensive, evidence-based overview to help readers make informed decisions about their health.
Anxiety manifests through a combination of psychological symptoms (excessive worry, racing thoughts, difficulty concentrating, irritability) and physical symptoms (rapid heartbeat, muscle tension, sweating, gastrointestinal distress, shortness of breath, dizziness). The physical manifestations often prompt individuals to seek medical care, believing they have a cardiac or respiratory condition.
## Common causes
Anxiety arises from complex interactions between biological, psychological, and environmental factors. The following causes are ranked approximately by frequency in clinical practice:
### 1. Generalized Anxiety Disorder (GAD)
The most commonly diagnosed anxiety condition, GAD involves chronic, excessive worry about multiple life domains. The pathophysiology involves dysregulation of the amygdala-prefrontal cortex circuit, altered GABAergic and serotonergic neurotransmission, and heightened activity in the hypothalamic-pituitary-adrenal (HPA) axis [2]. Genetic heritability is estimated at 30–40%.
### 2. Situational / Stress-related anxiety
Acute life stressors — job loss, relationship difficulties, financial pressure, health concerns — trigger the sympathetic nervous system's "fight-or-flight" response. Sustained cortisol elevation from chronic stress can sensitize neural fear circuits, lowering the threshold for future anxiety responses.
### 3. Medical conditions
Numerous medical conditions produce anxiety symptoms through direct physiological mechanisms:
- **Thyroid disorders** (hyperthyroidism): Excess thyroid hormone increases metabolic rate and catecholamine sensitivity
- **Cardiovascular conditions**: Arrhythmias, mitral valve prolapse, heart failure
- **Respiratory conditions**: Asthma, COPD, pulmonary embolism
- **Neurological conditions**: Vestibular disorders, temporal lobe epilepsy
- **Endocrine disorders**: Pheochromocytoma, hypoglycemia, Cushing's syndrome
### 4. Substance-induced anxiety
Caffeine, stimulants (amphetamines, cocaine), cannabis (especially high-THC strains), alcohol withdrawal, benzodiazepine withdrawal, and certain medications (corticosteroids, thyroid hormones, decongestants, some asthma medications) can provoke or exacerbate anxiety through sympathomimetic or GABAergic mechanisms.
### 5. Panic Disorder
Recurrent unexpected panic attacks — sudden surges of intense fear peaking within minutes — accompanied by persistent worry about future attacks. Involves hypersensitivity of the brain's suffocation alarm system and interoceptive conditioning [2].
### 6. Social Anxiety Disorder
Marked fear of social situations where one might be scrutinized. Involves heightened amygdala reactivity to perceived social threat and deficient prefrontal regulatory control.
### 7. Other psychiatric comorbidities
Anxiety commonly co-occurs with major depressive disorder (up to 60% comorbidity), PTSD, OCD, and ADHD. Shared neurobiological substrates — particularly serotonin and norepinephrine pathways — underlie this overlap.
## RED FLAGS
The following signs warrant **immediate medical attention** (call emergency services or go to the ER):
- **Chest pain, pressure, or tightness** — especially with jaw/arm pain, shortness of breath, or diaphoresis (must rule out myocardial infarction)
- **Active suicidal ideation** — thoughts of self-harm, a plan, or intent to act
- **Severe panic with inability to breathe** — cyanosis, oxygen desaturation
- **Sudden severe headache** ("thunderclap") with anxiety — may indicate subarachnoid hemorrhage
- **Symptoms following ingestion of substances** — possible overdose or poisoning
- **Signs of anaphylaxis** — anxiety with hives, throat swelling, hypotension
- **New-onset confusion, disorientation, or psychosis** alongside anxiety
- **Seizures** occurring with anxious episodes
- **Severe alcohol or benzodiazepine withdrawal** — tremors, tachycardia, hallucinations, fever (risk of delirium tremens, which can be fatal)
- **Heart rate >150 bpm at rest** or new-onset arrhythmia
> **Important:** Many of these red flags mimic anxiety symptoms. When in doubt, seek emergency evaluation. It is always safer to rule out life-threatening conditions.
## Self-care at home
Evidence-based non-pharmacological strategies can significantly reduce anxiety severity. A 2017 meta-analysis demonstrated that regular exercise produces clinically meaningful anxiolytic effects comparable to some first-line treatments [5].
### Physical activity
- **Aerobic exercise**: 150 minutes/week of moderate-intensity activity (brisk walking, cycling, swimming) reduces anxiety symptoms significantly [5]
- **Resistance training**: 2–3 sessions per week has demonstrated anxiolytic benefits
- **Yoga**: Multiple RCTs support yoga as an adjunctive anxiety treatment
### Breathing and relaxation techniques
- **Diaphragmatic breathing**: Slow breathing (4–6 breaths/minute) activates the parasympathetic nervous system via vagal stimulation
- **Progressive muscle relaxation (PMR)**: Systematically tensing and releasing muscle groups reduces physiological arousal
- **4-7-8 breathing technique**: Inhale 4 seconds, hold 7 seconds, exhale 8 seconds
### Cognitive-behavioral strategies
- **Thought challenging**: Identifying and reframing catastrophic or distorted thinking patterns
- **Worry scheduling**: Designating a specific 15–20 minute daily period for worry, postponing anxious thoughts to that window
- **Exposure practice**: Gradually confronting avoided situations in a systematic hierarchy
Cognitive-behavioral therapy (CBT) principles, even self-directed, have strong evidence for anxiety reduction [3].
### Lifestyle modifications
- **Sleep hygiene**: Maintain consistent sleep-wake times; aim for 7–9 hours. Sleep deprivation significantly worsens anxiety
- **Caffeine reduction**: Limit to <200 mg/day or eliminate entirely; caffeine antagonizes adenosine receptors and activates the sympathetic nervous system
- **Alcohol reduction**: While initially anxiolytic, alcohol disrupts sleep architecture and causes rebound anxiety
- **Digital detox**: Limiting news consumption and social media, particularly before bed
- **Mindfulness meditation**: 10–20 minutes daily; meta-analyses support moderate effect sizes for anxiety reduction
### Social and environmental
- Maintaining social connections and support networks
- Spending time in nature (evidence supports cortisol reduction)
- Journaling or expressive writing
- Structured daily routines to reduce uncertainty
## OTC medications that help
Over-the-counter options for anxiety are limited in efficacy compared to prescription medications. The following may provide modest relief for mild anxiety, though evidence varies in quality.
| Class | Example | Typical Adult Dose | Mechanism | Notes / Contraindications |
|-------|---------|-------------------|-----------|---------------------------|
| Antihistamine (sedating) | Diphenhydramine (Benadryl) | 25–50 mg as needed (max 300 mg/day) | H1 receptor antagonism; CNS depression | Sedation, anticholinergic effects. Avoid in elderly, BPH, glaucoma. Not for long-term use |
| Herbal — Lavender | Silexan (lavender oil capsule) | 80–160 mg/day | Modulates voltage-gated calcium channels; inhibits NMDA receptors | Generally well tolerated; GI discomfort possible. Evidence from several RCTs supports efficacy for subsyndromal anxiety [4] |
| Herbal — Passionflower | Passiflora incarnata extract | 250–500 mg/day | GABAergic activity | Limited but promising evidence; may cause sedation. Avoid in pregnancy |
| Herbal — Chamomile | Matricaria chamomilla extract | 220–1,100 mg/day | Apigenin binds benzodiazepine receptors | One RCT showed benefit in GAD; generally safe. Avoid with anticoagulants |
| Amino acid | L-Theanine | 200–400 mg/day | Promotes alpha brain waves; modulates glutamate and GABA | Found in green tea; well tolerated; modest evidence |
| Mineral supplement | Magnesium (glycinate or citrate) | 200–400 mg/day | NMDA receptor modulation; HPA axis regulation | May help if deficient; diarrhea at high doses (especially citrate). Check renal function |
| Herbal — Valerian | Valeriana officinalis | 300–600 mg before bed | Weak GABA reuptake inhibition | Primarily for sleep-related anxiety; inconsistent evidence. Avoid with sedatives |
**Important caveats:**
- OTC options are generally appropriate only for mild, situational anxiety
- Herbal products are not standardized; quality varies between brands
- Always inform your healthcare provider about supplements, as interactions with prescription medications are possible
- Diphenhydramine should not be used regularly for anxiety due to tolerance, cognitive effects, and anticholinergic burden
## Prescription options
Prescription anxiolytics are indicated when anxiety significantly impairs daily functioning, when self-care measures are insufficient, or when a formal anxiety disorder is diagnosed. Treatment should be initiated and monitored by a qualified clinician (primary care physician, psychiatrist, or psychiatric nurse practitioner).
| Class | Examples | Typical Adult Dose Range | Mechanism | Key Considerations |
|-------|----------|--------------------------|-----------|--------------------|
| SSRI | Sertraline, Escitalopram, Paroxetine | Sertraline 50–200 mg/day; Escitalopram 10–20 mg/day | Serotonin reuptake inhibition | First-line treatment. 2–4 weeks to full effect. May initially worsen anxiety. Sexual side effects, GI upset |
| SNRI | Venlafaxine XR, Duloxetine | Venlafaxine 75–225 mg/day; Duloxetine 60–120 mg/day | Serotonin and norepinephrine reuptake inhibition | First-line. Monitor blood pressure. Discontinuation syndrome if stopped abruptly |
| Buspirone | Buspirone | 15–60 mg/day (divided BID-TID) | 5-HT1A partial agonist | Non-sedating, no dependence potential. Takes 2–4 weeks for effect. Specifically for GAD |
| Benzodiazepine | Alprazolam, Lorazepam, Clonazepam | Varies by agent | GABA-A receptor positive allosteric modulator | Rapid onset. Reserved for short-term or acute use due to dependence, tolerance, withdrawal risk. Not first-line |
| Pregabalin | Pregabalin (Lyrica) | 150–600 mg/day | Voltage-gated calcium channel α2δ subunit ligand | Approved for GAD in Europe (not FDA-approved for anxiety in US). Evidence supports efficacy [4] |
| Hydroxyzine | Hydroxyzine (Vistaril) | 25–100 mg up to QID | H1 antihistamine; CNS depressant | Non-addictive alternative for acute anxiety. Sedation is primary side effect |
| Beta-blocker | Propranolol | 10–40 mg as needed | β-adrenergic antagonism | Primarily for performance anxiety (physical symptoms). Does not treat cognitive worry |
| Tricyclic antidepressant | Imipramine, Clomipramine | Varies | Multiple monoamine reuptake inhibition | Second/third-line. More side effects. Useful for panic disorder and comorbid conditions |
**Treatment principles:**
- SSRIs and SNRIs are considered first-line pharmacotherapy for most anxiety disorders based on efficacy, safety, and tolerability [4, 6]
- Benzodiazepines should generally be limited to short-term use (2–4 weeks) or acute crisis management due to dependence risk
- Combination of medication with CBT produces superior outcomes to either alone [3]
- Treatment duration is typically 12 months minimum after remission; many patients benefit from longer-term maintenance
- Medication changes should always be made under clinician supervision; abrupt discontinuation of SSRIs, SNRIs, or benzodiazepines can cause significant withdrawal symptoms
## Lab tests typically ordered
When a patient presents with new-onset or unexplained anxiety, clinicians may order laboratory tests to exclude medical conditions that mimic or exacerbate anxiety:
| Test | Rationale | Link |
|------|-----------|------|
| Thyroid function (TSH, free T4) | Hyperthyroidism is a common and treatable medical mimic of anxiety | [Thyroid Panel](/tests/thyroid-panel) |
| Complete blood count (CBC) | Anemia can cause tachycardia, fatigue, and anxious symptoms | [CBC](/tests/complete-blood-count) |
| Comprehensive metabolic panel (CMP) | Electrolyte imbalances (calcium, magnesium), glucose abnormalities, liver/kidney function | [Metabolic Panel](/tests/comprehensive-metabolic-panel) |
| Fasting glucose / HbA1c | Hypoglycemia and poorly controlled diabetes can trigger anxiety-like episodes | [HbA1c](/tests/hba1c) |
| Urine drug screen | Stimulant use or substance withdrawal as causative factors | [Drug Screen](/tests/urine-drug-screen) |
| Vitamin D level | Deficiency associated with mood and anxiety symptoms in observational studies | [Vitamin D](/tests/vitamin-d) |
| Cortisol (AM) | Cushing's syndrome or adrenal insufficiency evaluation if clinically suspected | [Cortisol](/tests/cortisol) |
| Ferritin | Iron deficiency (even without anemia) linked to anxiety and restless symptoms | [Ferritin](/tests/ferritin) |
| ECG / Cardiac monitoring | Rule out arrhythmias when palpitations are prominent | [ECG](/tests/electrocardiogram) |
| B12 and folate | Deficiency can cause neuropsychiatric symptoms including anxiety | [Vitamin B12](/tests/vitamin-b12) |
Not all tests are necessary for every patient. Test selection should be guided by clinical presentation, history, and physical examination findings.
## Special populations
### Children and adolescents
- Anxiety disorders affect approximately 7% of children aged 3–17 years
- Presentation may differ from adults: irritability, school refusal, somatic complaints (stomachaches, headaches), clinginess, tantrums
- **First-line treatment** is CBT adapted for developmental level; strong evidence supports its efficacy in pediatric populations
- **Pharmacotherapy**: SSRIs (specifically fluoxetine, sertraline, and fluvoxamine) have the strongest evidence in pediatric anxiety. Dosing should always be determined by a pediatric clinician and started at lower doses than adult ranges
- **FDA Black Box Warning**: All antidepressants carry a warning for increased suicidal ideation in patients under 25; close monitoring is essential during initiation
- Benzodiazepines are generally avoided in children due to paradoxical reactions and developmental concerns
- Pediatric dosing of any medication should be managed exclusively by a qualified pediatric provider
### Pregnancy and breastfeeding
- Anxiety disorders are common in pregnancy (prevalence ~15–20%)
- **Non-pharmacological approaches** (CBT, relaxation, exercise) are preferred as first-line
- **SSRIs**: Generally considered when benefits outweigh risks. Sertraline and escitalopram are often preferred due to more reassuring safety data. Paroxetine is associated with a small increased risk of cardiac malformations (FDA Category D)
- **Benzodiazepines**: Associated with potential risks including neonatal sedation, withdrawal, and possible (debated) cleft palate risk with first-trimester exposure. Generally avoided when possible
- **Buspirone**: Limited human pregnancy data; generally not first choice
- All medication decisions in pregnancy should involve shared decision-making between the patient, obstetrician, and psychiatrist
- Untreated maternal anxiety itself carries risks: preterm birth, low birth weight, postpartum complications
- **Breastfeeding**: Sertraline has the lowest known infant exposure via breast milk; individual risk-benefit assessment is essential
### Elderly (≥65 years)
- Anxiety in older adults is often underdiagnosed and frequently comorbid with depression, cognitive decline, or medical illness
- **Pharmacotherapy considerations**:
- SSRIs: Start at half the usual adult dose; escitalopram preferred for fewer drug interactions
- Benzodiazepines: **Strongly discouraged** per the Beers Criteria due to falls risk, cognitive impairment, delirium, and paradoxical agitation
- Buspirone: May be a safer anxiolytic option in this population
- Anticholinergic medications (diphenhydramine, hydroxyzine at high doses): Avoid due to cognitive impairment, urinary retention, constipation
- Fall risk must be assessed with any sedating medication
- Polypharmacy interactions are a major concern; medication reconciliation is critical
- CBT adapted for older adults is effective and should be offered
### Athletes
- Performance anxiety is common and may not constitute a disorder
- **Propranolol** may be used for performance-related physical symptoms (tremor, tachycardia) but is banned by WADA in certain sports (archery, shooting)
- Exercise itself is anxiolytic, but overtraining syndrome can paradoxically increase anxiety
- SSRIs are not prohibited by most anti-doping agencies but may affect performance through fatigue or weight changes
- Caffeine and stimulant pre-workout supplements may worsen anxiety
- Athletes should be screened for relative energy deficiency in sport (RED-S), which can present with mood and anxiety symptoms
- Sleep disruption from travel or competition schedules may exacerbate anxiety
## When to escalate
Use the following thresholds to guide escalation decisions:
### Self-manage at home
- Mild, situational anxiety that resolves with removal of stressor
- Anxiety that responds to self-care measures within 1–2 weeks
- No impairment in daily functioning, work, or relationships
### Schedule a GP appointment (within 1–2 weeks)
- Anxiety persisting >2 weeks despite self-care efforts
- Anxiety beginning to interfere with work, sleep, or relationships
- New physical symptoms (palpitations, GI distress) with anxiety
- Desire to discuss medication options
- Family history of anxiety disorders and increasing symptoms
### Same-day or next-day medical appointment
- Panic attacks occurring for the first time
- Significant functional impairment (unable to work, leave home, or maintain responsibilities)
- Anxiety accompanied by new physical symptoms requiring medical evaluation
- Worsening symptoms despite current treatment
- Medication side effects causing concern
### Urgent care or ER — seek immediate help
- Suicidal or self-harm thoughts (call 988 Suicide & Crisis Lifeline in the US)
- Chest pain or symptoms that could indicate cardiac emergency
- Severe panic with sense of impending doom and inability to self-regulate
- Symptoms of substance withdrawal (tremors, seizures, hallucinations)
- Psychotic symptoms (hallucinations, delusions) accompanying anxiety
- Inability to eat, drink, or care for oneself due to severity
> **Crisis resources:** In the US, call or text **988** (Suicide & Crisis Lifeline). In the UK, call **116 123** (Samaritans). For immediate danger, call your local emergency number.
## References
[1] Bandelow B, Michaelis S. Epidemiology of anxiety disorders in the 21st century. Dialogues Clin Neurosci. 2015;17(3):327-335. PMID:26487813
[2] Craske MG, Stein MB. Anxiety. Lancet. 2016;388(10063):3048-3059. PMID:27349358
[3] Hofmann SG, Smits JAJ. Cognitive-behavioral therapy for adult anxiety disorders: a meta-analysis of randomized placebo-controlled trials. J Clin Psychiatry. 2008;69(4):621-632. PMID:18363421
[4] Bandelow B, Reitt M, Röver C, Michaelis S, Görlich Y, Wedekind D. Efficacy of treatments for anxiety disorders: a meta-analysis. Int Clin Psychopharmacol. 2015;30(4):183-192. PMID:25932596
[5] Stubbs B, Vancampfort D, Rosenbaum S, et al. An examination of the anxiolytic effects of exercise for people with anxiety and stress-related disorders: A meta-analysis. Psychiatry Res. 2017;249:102-108. PMID:28088704
[6] National Institute for Health and Care Excellence (NICE). Generalised anxiety disorder and panic disorder in adults: management. Clinical guideline [CG113]. 2011, updated 2020. Available at: nice.org.uk/guidance/cg113
[7] Kessler RC, Petukhova M, Sampson NA, Zaslavsky AM, Wittchen HU. Twelve-month and lifetime prevalence and lifetime morbid risk of anxiety and mood disorders in the United States. Int J Methods Psychiatr Res. 2012;21(3):169-184. PMID:22865617
[8] American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Arlington, VA: American Psychiatric Publishing; 2013.
[9] Baldwin DS, Anderson IM, Nutt DJ, et al. Evidence-based pharmacological treatment of anxiety disorders, post-traumatic stress disorder and obsessive-compulsive disorder: a revision of the 2005 guidelines from the British Association for Psychopharmacology. J Psychopharmacol. 2014;28(5):403-439. PMID:24713617
---
*Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment of anxiety or any medical condition.*
