Dyspnea (Shortness of Breath): Causes, Red Flags & When to Act

Dyspnea—difficulty breathing—ranges from mild exertional discomfort to life-threatening emergency. It's a symptom, not a diagnosis.

Major Cause Categories

1. Respiratory: Asthma, COPD, pneumonia, pulmonary embolism, pneumothorax, interstitial lung disease.
2. Cardiac: Heart failure, coronary artery disease, arrhythmias, pericardial effusion, valvular disease.
3. Allergic/Anaphylactic: Airway swelling, bronchospasm—requires epinephrine immediately.
4. Psychogenic: Anxiety, panic disorder, hyperventilation syndrome—diagnosis of exclusion.
5. Other: Obesity, neuromuscular disease (ALS, myasthenia), anemia, metabolic acidosis, deconditioning.

Red Flags — Seek Emergency Care

• Sudden, severe onset
• Inability to speak in full sentences
• Cyanosis (blue lips/nails)
• Chest pain, syncope, confusion
• Stridor or wheezing not relieved by inhaler

Persistent or unexplained dyspnea always warrants medical evaluation to identify and treat the underlying cause.