Symptom · Chest
Shortness of breath
Also known as: breathlessness, dyspnoea, dyspnea
The sensation of not getting enough air. It arises when breathing demands more effort than expected, when the blood carries too little oxygen or too much carbon dioxide, or when the heart cannot keep up. Speed of onset is the key clue: seconds, hours, days or months.
What it is
The sensation of not getting enough air. It arises when breathing demands more effort than expected, when the blood carries too little oxygen or too much carbon dioxide, or when the heart cannot keep up. Speed of onset is the key clue: seconds, hours, days or months.
Common causes
AsthmaWheeze, cough and tightness that come and go, worse at night or with triggers.
Chest infections and pneumoniaCough, fever and breathlessness over days.
COPDProgressive breathlessness on exertion in smokers, with chronic cough.
Heart failureBreathless lying flat, waking at night gasping, swollen ankles.
Anaemia and deconditioningGradual breathlessness on effort without chest signs.
Anxiety and hyperventilationAir hunger with tingling fingers and light-headedness.
Less common causes
Pulmonary embolismSudden breathlessness with pleuritic pain, fast pulse, sometimes a swollen leg.
PneumothoraxSudden one-sided breathlessness and chest pain.
Heart attack or arrhythmiaBreathlessness can be the main symptom, especially in women, the elderly and people with diabetes.
Anaphylaxis or airway obstructionSwelling of lips and tongue, stridor, hives.
Interstitial lung diseaseSlowly progressive breathlessness with a dry cough and crackles.
Often occurs with
Seek urgent care if
- Breathlessness that comes on suddenly or is severe at rest
- Blue lips, confusion, or inability to speak in full sentences
- Breathlessness with chest pain, coughing blood or a swollen leg
- Swelling of the face or tongue, or noisy breathing (stridor)
- Oxygen saturation below 92% on a home oximeter
Conditions to read about
AsthmaChronic obstructive pulmonary disease (COPD)PneumoniaHeart failurePulmonary embolismAnaemiaHeart attack (myocardial infarction)
How it is investigated
Educational content. This page explains what a symptom can mean so that the anatomy and the medical reasoning make sense. It cannot tell you what is causing yours: only a clinician who can examine you and order tests can do that.