What is the differential diagnosis for panic attacks?

Differential Diagnosis for Panic Attacks

Primary Psychiatric Conditions

When evaluating panic attacks, first distinguish panic disorder from other anxiety disorders, then systematically exclude medical mimics and psychiatric comorbidities. 1

Panic Disorder vs. Other Anxiety Disorders

• Panic Disorder is characterized by recurrent unexpected panic attacks with abrupt surge of intense fear reaching peak intensity within 10 minutes, accompanied by persistent fear of future attacks and significant behavioral changes to avoid situations where attacks might occur. 2, 3

• Generalized Anxiety Disorder (GAD) involves chronic, pervasive worry about multiple everyday topics with physical symptoms (fatigue, sleep disturbances, irritability, concentration difficulties) but lacks discrete panic attacks as the defining feature; patients with GAD may experience occasional panic attacks, but the core pathology is excessive worry rather than fear of the attacks themselves. 2, 1, 3

• Social Anxiety Disorder features anxiety triggered specifically by social evaluation situations where the individual fears acting in humiliating or embarrassing ways; panic-like symptoms may occur but only in these specific social contexts. 2, 3, 4

• Agoraphobia is characterized by excessive fear about being in situations (crowds, enclosed spaces) where escape might be difficult or help unavailable should panic-like symptoms occur; this develops in 30-50% of panic disorder patients. 2, 3

• Specific Phobia involves excessive fear reliably elicited by specific environmental stimuli (animals, natural environments, blood/injections, situational triggers), distinguishing it from the unexpected nature of panic disorder attacks. 2, 5

Cultural Considerations in Panic Presentation

• Cultural syndromes significantly influence how panic attacks are experienced and reported; European Americans commonly report heart-focused panic attacks, while Southeast Asian populations more often express somatic-focused panic attacks related to beliefs about blocked wind or chi (khyâl attacks in Cambodia, trung gió attacks in Vietnam). 2, 3

• Ataque de nervios in Caribbean Latino populations may be triggered by interpersonal arguments and includes panic symptoms; 80% of patients with ataques de nervios endorse postattack sequelae similar to panic disorder criteria. 2

• Somatic presentations are more common in non-Western populations and should not be dismissed as "atypical" but recognized as culturally-specific expressions of the same underlying panic phenomenon. 3

Medical Conditions That Mimic Panic Attacks

Always exclude medical causes before confirming a psychiatric diagnosis, as several conditions produce identical autonomic symptoms. 1, 6

Endocrine Disorders

• Hyperthyroidism causes anxiety symptoms including palpitations, tremor, sweating, heat intolerance, and weight loss; order thyroid function tests (TSH, free T4) if clinical presentation suggests thyroid dysfunction. 1, 4

• Hypoglycemia/Diabetes triggers panic-like symptoms with autonomic activation (tremor, diaphoresis, palpitations, anxiety); check fasting glucose and HbA1c if episodes correlate with meals or fasting states. 1, 4

• Pheochromocytoma produces episodic hypertension, headache, diaphoresis, and palpitations; measure plasma-free metanephrine and urinary vanillylmandelic acid to exclude this rare but important mimic. 2

Cardiovascular Disorders

• Cardiac arrhythmias (supraventricular tachycardia, atrial fibrillation, ventricular tachycardia) can initiate or mimic panic attacks; distinguish by ECG findings, relationship to exertion, and absence of psychological triggers. 1, 7

• Acute coronary syndrome (ACS) can be clinically indistinguishable from panic attacks without appropriate investigations; panic disorder is an independent risk factor for subsequent coronary events with higher mortality rates, making this distinction critical. 7

• Pulmonary embolism presents with acute dyspnea, chest pain, and anxiety; consider D-dimer and CT pulmonary angiography if risk factors present. 2

Neurological Conditions

• Seizure disorders (particularly temporal lobe epilepsy) can present with episodic fear, autonomic symptoms, and altered consciousness; obtain EEG if episodes include loss of awareness or postictal confusion. 2

• Vestibular disorders cause dizziness, vertigo, and secondary anxiety; distinguish by positional triggers, nystagmus, and absence of other panic symptoms. 6

Respiratory Conditions

• Asthma and chronic obstructive pulmonary disease (COPD) cause dyspnea and can trigger secondary panic; however, bronchospasm is generally absent in pure panic attacks unless comorbid asthma exists. 2

• Hyperventilation syndrome overlaps significantly with panic attacks but may be distinguished by carpopedal spasm, perioral numbness, and respiratory alkalosis on blood gas. 2

Systemic Conditions

• Anaphylaxis presents with acute onset of urticaria, angioedema, bronchospasm, and hypotension; distinguished from panic by cutaneous manifestations (urticaria, flush, pruritus) and potential bradycardia rather than tachycardia. 2

• Systemic mastocytosis causes episodic flushing, hypotension, and gastrointestinal symptoms; measure serum tryptase levels (peak 60-90 minutes after onset, persist to 6 hours) to distinguish from panic attacks where tryptase remains normal. 2

• Carcinoid syndrome produces flushing, diarrhea, and bronchospasm; check serum serotonin and urinary 5-hydroxyindoleacetic acid to exclude this diagnosis. 2

Substance-Induced Presentations

• Caffeine excess directly provokes panic-like symptoms (tremor, palpitations, anxiety); obtain detailed history of caffeine intake from all sources (coffee, tea, energy drinks, medications). 4, 6

• Stimulant medications (amphetamines, methylphenidate, decongestants) and illicit drugs (cocaine, methamphetamine) produce identical autonomic symptoms; screen for substance use in all patients. 2, 4

• Alcohol or benzodiazepine withdrawal causes severe anxiety, tremor, autonomic instability, and potential seizures; assess for substance dependence and withdrawal timeline. 3, 4

• Medication side effects including akathisia from antidepressants, antipsychotics, or antiemetics can mimic panic attacks with severe restlessness and anxiety. 7

Other Psychiatric Differential Diagnoses

Mood Disorders

• Major Depressive Disorder co-occurs in 50-60% of panic disorder cases; use PHQ-9 to screen for depression, as comorbid depression significantly increases suicide risk. 3, 4

• Determine whether anxiety is primary or secondary to depression by establishing temporal sequence; if depression preceded anxiety symptoms, consider anxiety as part of the affective disorder. 5

Trauma-Related Disorders

• Post-Traumatic Stress Disorder (PTSD) frequently includes panic attacks triggered by trauma reminders; in many cultures, panic attacks are expected after traumatic exposures, potentially leading to underdiagnosis of panic disorder if all attacks are attributed to trauma. 2, 3

Somatoform Disorders

• Somatic Symptom Disorder involves persistent somatic complaints with excessive thoughts, feelings, or behaviors related to symptoms; distinguish from panic disorder by chronicity and focus on physical symptoms rather than fear of attacks. 5

• Illness Anxiety Disorder (hypochondriasis) involves preoccupation with having a serious illness; patients may experience panic-like symptoms but the core pathology is health anxiety rather than discrete panic attacks. 5

Psychotic Disorders

• Schizophrenia or other psychotic disorders may include anxiety symptoms; the presence of hallucinations, delusions, or disorganized thinking distinguishes these from primary panic disorder. 2

Other Anxiety-Related Conditions

• Obsessive-Compulsive Disorder is characterized by recurrent unwanted thoughts and ritualized repetitive acts; anxiety occurs in response to obsessions or when prevented from performing compulsions, not as unexpected panic attacks. 5

• Adjustment Disorder with Anxious Mood involves anxiety symptoms as a direct result of an identifiable stressor occurring within 3 months of the stressor; symptoms resolve within 6 months after the stressor ends. 5

Vasovagal Syncope

• Vasodepressor (vasovagal) reactions are the condition most commonly confused with panic attacks; distinguish by absence of urticaria, presence of bradycardia (not tachycardia), cool and pale skin (not flushed), and normal or increased blood pressure. 2

Critical Red Flags Requiring Immediate Attention

• Suicidal ideation or self-harm behaviors require immediate safety assessment and intervention; panic disorder significantly increases suicide risk, particularly when comorbid with depression or GAD. 2, 1, 3, 4

• Severe agitation, psychosis, or confusion (delirium) warrant emergency evaluation by a licensed mental health professional or psychiatrist. 2, 4

• Risk of harm to self or others necessitates facilitation of a safe environment, one-to-one observation, and emergency psychiatric evaluation. 2

Diagnostic Approach Algorithm

1. Obtain detailed history of all ingestants (foods, drugs, caffeine) several hours before episodes, activities preceding events (exercise, sexual activity), and any bites or stings; the history is the most important tool and takes precedence over diagnostic tests. 2

2. Screen for medical mimics by ordering thyroid function tests, fasting glucose, ECG, and considering serum tryptase if anaphylaxis suspected (measure 1-2 hours after symptom onset). 2, 1

3. Assess for substance use including alcohol, benzodiazepines, stimulants, and caffeine; directly ask about use patterns and withdrawal symptoms. 3, 4

4. Screen for psychiatric comorbidities using validated tools: PHQ-9 for depression, GAD-7 for generalized anxiety (validated for patients ≥8 years), and assess for PTSD and substance use disorders. 1, 3, 4

5. Evaluate functional impairment in work performance, social relationships, academic functioning, and quality of life to distinguish clinically significant anxiety from normal developmental fears. 3, 4

6. Consider cultural context of symptom presentation and perceived triggers; ask about cultural beliefs regarding wind, chi, or other culture-specific explanations for symptoms. 2, 3

7. Assess suicide risk in all patients, particularly those with comorbid depression or GAD; panic disorder is considered a risk factor for suicide by multiple authorities. 1, 3, 4

Common Diagnostic Pitfalls

• Missing medical mimics such as hyperthyroidism, cardiac arrhythmias, and hypoglycemia that present with anxiety-like symptoms; always order appropriate laboratory and diagnostic tests before confirming psychiatric diagnosis. 1, 4

• Dismissing somatic presentations in non-Western populations as "atypical" when they represent culturally-specific expressions of panic. 3

• Failing to recognize comorbid depression which occurs in 50-60% of panic disorder cases and significantly increases suicide risk. 3

• Attributing all panic attacks to trauma in PTSD patients, missing comorbid panic disorder that requires specific treatment. 2

• Overlooking substance-induced presentations from caffeine, stimulants, or withdrawal states. 4, 6