Symptom Combination

Loss Of Consciousness and Shortness Of Breath: Causes, Conditions & When to See a Doctor

Shortness of breath combined with loss of consciousness suggests massive pulmonary embolism, acute decompensated heart failure with syncope, tension pneumothorax, or hypoxic syncope. Either symptom alone demands urgent evaluation — combined, they represent a potential cardiac or pulmonary catastrophe.

→ Loss Of Consciousness Overview → Shortness Of Breath Overview

Possible Causes of Loss Of Consciousness and Shortness Of Breath

Conditions that commonly cause both symptoms together

1Massive pulmonary embolism with right heart failure and syncope
2Tension pneumothorax with mediastinal shift and circulatory collapse
3Acute decompensated heart failure with orthostatic syncope
4Severe asthma or COPD exacerbation with hypoxic syncope
5Carbon monoxide poisoning with both hypoxia and syncope

Emergency Red Flags

Seek immediate medical attention if you experience any of these

Syncope during or immediately after a bout of severe dyspnea

Tachycardia + hypoxia + hypotension (PE triad)

Unilateral absent breath sounds (pneumothorax)

Cyanosis accompanying dyspnea before syncope

Recent long-haul flight or prolonged immobility

When to See a Doctor

Schedule a medical consultation if you notice these signs

Call 112/911 — massive PE requires thrombolysis or embolectomy

Administer high-flow oxygen immediately

IV access and monitoring prior to imaging

CT pulmonary angiography is the gold standard for PE diagnosis

Conditions That Cause Both Loss Of Consciousness and Shortness Of Breath

2 conditions are associated with this symptom combination

Pulmonary Embolism

Massive PE classically presents with syncope + dyspnea + tachycardia

Tension Pneumothorax

Respiratory failure and circulatory collapse causing both symptoms

Explore Individual Symptoms

In-depth pages for each symptom in this combination

Loss Of Consciousness — Full Overview Causes Treatment When to See a Doctor Related Questions

Shortness Of Breath — Full Overview Causes Treatment When to See a Doctor Related Questions

Clinical Matches — Authority Pages

Condition-level differential and comparison resources for this combination

⚠ Dangerous — Rule Out First:

Pulmonary Embolism

Differential analyses:

🔬Pulmonary Embolism: differential →

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