Shortness of Breath
Shortness of Breath: A Complete Patient Guide
Shortness of breath (breathlessness or dyspnoea) is the uncomfortable awareness of breathing: feeling you cannot get enough air, or that breathing takes effort. Some breathlessness is normal with vigorous exercise, but breathlessness that is new, worsening, out of proportion to effort, or present at rest needs a proper explanation.
The two most common groups of causes are the heart and the lungs, and they can coexist. Cardiac causes include heart failure, coronary artery disease, heart valve disease, heart rhythm problems such as atrial fibrillation, cardiomyopathy, pericardial disease and pulmonary hypertension. Lung causes include asthma, COPD, interstitial lung disease, infection and pulmonary embolism. Anaemia, obesity, thyroid disease, deconditioning and anxiety are also common contributors.
Because breathlessness is such a common and non-specific symptom, assessment focuses on a careful history and a small number of targeted tests, usually an ECG, blood tests including a natriuretic peptide (NT-proBNP), a chest X-ray, lung function tests and an echocardiogram. Identifying a heart cause matters because many are very treatable.
The pattern of breathlessness gives clues to its cause.
Heart-related patterns
Breathlessness on exertion that has gradually worsened, reducing how far you can walk or climb stairs
Breathlessness lying flat (orthopnoea), needing extra pillows, or waking at night gasping (paroxysmal nocturnal dyspnoea)
Associated ankle swelling, tiredness, weight gain, chest tightness or palpitations
Lung-related patterns
Wheeze, cough with or without phlegm, chest tightness and variable symptoms
A history of smoking, asthma, COPD or occupational exposures
Fever, productive cough or pleuritic chest pain suggesting infection
Other clues
Pale, tired and breathless with minimal effort: anaemia
Sudden breathlessness with pleuritic chest pain or a swollen calf: pulmonary embolism
Breathlessness with a feeling of panic, tingling or rapid breathing: anxiety or hyperventilation, once other causes have been excluded
Breathlessness can have more than one cause at once, which is why a thorough assessment helps.
Heart causes
Heart failure (weak or stiff heart)
Coronary artery disease and angina (breathlessness may be the only symptom)
Valve disease, such as aortic stenosis and mitral regurgitation
Atrial fibrillation and other rhythm disturbances, cardiomyopathies and pericardial disease
Pulmonary hypertension and congenital heart disease
Lung and blood vessel causes
Asthma, COPD, bronchiectasis and interstitial lung disease
Pneumonia, pleural effusion and pneumothorax
Pulmonary embolism (a clot in the lungs)
Other causes
Anaemia, an overactive or underactive thyroid, and kidney disease
Obesity and deconditioning
Anxiety and panic, and obesity hypoventilation
Medicines (for example, some chemotherapy and amiodarone)
The aim is to establish whether the heart, lungs or something else is responsible.
1. History and examination
Your cardiologist will explore how far you can walk, whether you are breathless lying flat, swelling, chest pain, palpitations, smoking and medicines. Pulse, blood pressure, oxygen level, heart sounds, lungs and swelling are examined.
2. ECG
An ECG checks for rhythm disturbance, previous heart attack and strain. A normal ECG makes heart failure with a weak heart unlikely.
3. Blood tests
A natriuretic peptide (NT-proBNP) blood test is used to assess the likelihood of heart failure. NICE advises that a level above 2,000 ng/L needs specialist assessment within 2 weeks, and a level of 400 to 2,000 ng/L within 6 weeks. Blood count, kidney, thyroid and liver function and blood sugar are also checked.
4. Echocardiogram
An echocardiogram shows how well the heart pumps and relaxes, the valves and the pressures in the lungs, and is the key test for a heart cause.
5. Lung tests and further heart tests
A chest X-ray and lung function tests (spirometry) are used to assess the lungs. If a cardiac cause is suspected, further tests may include stress echo, exercise ECG, CT coronary angiography, cardiac MRI or bubble echo.
Treatment depends entirely on the cause, which is why the investigations matter.
If it is the heart
Heart failure: foundational medicines, diuretics for fluid and treatment of the cause
Coronary disease: antiplatelet, statin, anti-anginal medicines, and stents or bypass in selected people
Valve disease: monitoring, and valve repair or replacement when indicated
Atrial fibrillation: stroke prevention, rate or rhythm control, cardioversion or ablation
If it is the lungs
Inhalers and other medicines for asthma and COPD, antibiotics for infection, anticoagulants for pulmonary embolism, and respiratory specialist care for interstitial lung disease.
If it is something else
Iron or other treatment for anaemia, thyroid treatment, weight loss and graded exercise for obesity and deconditioning, and psychological therapies for anxiety-related breathlessness.
General measures
Stop smoking, get vaccinated against influenza, COVID-19 and pneumococcus, and stay as active as you can
Pulmonary or cardiac rehabilitation helps both heart and lung causes
Keep active. Regular, gently increasing activity improves breathlessness in both heart and lung conditions.
Pace yourself. Break tasks into steps and rest between them.
Breathing techniques such as pursed-lip breathing and a slow, relaxed pattern can help during an episode.
Weigh yourself daily if you have heart failure, and report a gain of more than about 2 kg in 3 days.
Sleep propped up if breathless when lying flat, and mention this to your doctor.
Stop smoking, and avoid smoky environments.
Take medicines as prescribed, and keep a record of your symptoms.
Support is available from the British Heart Foundation, Asthma + Lung UK and the NHS.
The outlook depends entirely on the cause. Many causes of breathlessness are highly treatable, and treatment usually improves symptoms considerably.
Heart causes such as heart failure, valve disease and atrial fibrillation respond well to modern treatment, particularly when diagnosed early.
Breathlessness caused by deconditioning, anaemia or anxiety often improves with the right approach.
Persistent unexplained breathlessness deserves repeated assessment, because multiple causes often coexist.
Early investigation, rather than waiting, gives the best chance of effective treatment.
Do not put persistent breathlessness down to age or lack of fitness without having it checked.
Arrange an assessment if you have:
Breathlessness that is new, worsening, or that limits what you can do
Breathlessness lying flat or waking you at night
Ankle swelling, weight gain, palpitations or chest tightness with breathlessness
A heart murmur, a history of heart disease, high blood pressure, diabetes or a family history of cardiomyopathy
A persistent cough or wheeze that has not been explained
If you are unsure
A cardiology assessment with an ECG and echocardiogram can quickly show whether the heart is responsible, and often provides reassurance.
These features suggest a more serious cause and call for urgent assessment.
Red flags
Rapidly worsening breathlessness over hours to days
Breathlessness at rest or on minimal effort
Chest pain, fainting or palpitations with the breathlessness
Swollen legs with a painful or red calf (possible clot)
Coughing blood or pink frothy phlegm
Blue or grey lips or face
What to do
Seek urgent assessment the same day. If symptoms are severe, call 999.
Breathlessness with the following needs emergency help.
Call 999 immediately if you have:
Severe breathlessness at rest, or you cannot speak in full sentences
Chest pain or pressure, especially with sweating or pain spreading to the arm or jaw
Fainting or collapse
Blue lips, confusion or drowsiness
Coughing up pink frothy phlegm or blood
Sudden breathlessness with a swollen, painful leg or after long travel or surgery
While waiting
Sit upright, loosen tight clothing and stay as calm as you can. Do not drive yourself.
Breathlessness is common, and the two main groups of causes are the heart and the lungs.
Heart causes include heart failure, coronary disease, valve disease and atrial fibrillation.
Breathlessness lying flat, waking at night or with swollen ankles points to a heart cause.
The key tests are an ECG, NT-proBNP blood test and echocardiogram, with lung tests.
NICE advises specialist assessment within 2 weeks if NT-proBNP is above 2,000 ng/L.
Anaemia, thyroid disease, obesity, deconditioning and anxiety are also common.
Treatment depends on the cause, and most are treatable.
Severe breathlessness, chest pain or fainting need 999.
Guidelines and sources
This page follows current UK and European guidance:
NICE NG106: Chronic heart failure in adults: diagnosis and management.
McDonagh TA et al. 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. European Heart Journal 2021;42:3599-3726.
These are the questions patients most often ask about shortness of breath.
What causes shortness of breath?
Most commonly heart or lung disease. Heart causes include heart failure, coronary disease, valve disease and atrial fibrillation. Anaemia, obesity, deconditioning and anxiety are also common.
How do I know if my shortness of breath is from the heart or lungs?
Breathlessness lying flat, waking at night, ankle swelling and tiredness suggest the heart, whereas wheeze, cough and a smoking history suggest the lungs. Tests such as an ECG, NT-proBNP and echocardiogram usually settle it.
When should I worry about shortness of breath?
If it is new, worsening, present at rest, or comes with chest pain, fainting, palpitations, leg swelling or blue lips. Call 999 for severe breathlessness.
What heart conditions cause shortness of breath?
Heart failure, coronary artery disease, heart valve disease, atrial fibrillation and other arrhythmias, cardiomyopathy, pericardial disease and pulmonary hypertension.
Can heart failure cause shortness of breath?
Yes, it is one of its main symptoms, usually with tiredness and swollen ankles. See our heart failure guide for more.
What tests are done for shortness of breath?
An ECG, blood tests including NT-proBNP, a chest X-ray, lung function tests and an echocardiogram. Further tests depend on what is found.
Can anxiety cause shortness of breath?
Yes, but it is a diagnosis made only after heart and lung causes have been considered. Anxiety and heart disease can coexist.
Is shortness of breath on exertion normal as you age?
Some reduction in stamina is normal, but a clear decline, or breathlessness on mild effort, is not just age and should be assessed.
Can I have a private assessment for breathlessness?
Yes. A telephone, video or face-to-face consultation in Peterborough or Corby can assess your breathlessness, with ECG reporting, echocardiography and other tests arranged as needed.
- Is my breathlessness due to my heart, lungs or something else?
- Which tests do I need, and what will they show?
- Do I have heart failure, valve disease or a rhythm problem?
- What treatment will help, and how quickly?
- How much exercise is safe for me?
- What symptoms should make me seek urgent help?
- When should I be reviewed again?
- Could anaemia, lung disease, a blood clot or a thyroid problem be contributing?
- Would losing weight, stopping smoking or other lifestyle changes help?
- Which symptoms should I track at home, such as weight, swelling or oxygen levels?
Where breathlessness can come from
Breathlessness has many causes. Heart and lung conditions are the most common, but anaemia, thyroid disease, kidney disease and low fitness can also be responsible, and more than one cause can be present together.
Heart or lungs? Clues from your symptoms
Certain features of the story point towards the heart and others towards the lungs. These are clues only. The history, examination and tests decide the cause.
How shortness of breath is investigated
Most people need a short series of tests. A normal NT-proBNP blood test makes heart failure unlikely, and an echocardiogram then shows how the heart pumps and whether a valve problem is present.
If you have shortness of breath, reduced stamina or ankle swelling, you may benefit from a telephone consultation or video consultation to discuss your symptoms in detail, or a face-to-face consultation in Peterborough or Corby for a more comprehensive assessment. Severe breathlessness needs a 999 call.
Investigations such as echocardiography, ECG reporting and stress echo may be recommended.
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Medically reviewed by Dr Salam Salloum, Consultant Cardiologist. Last updated: . This page is for general information and does not replace personal medical advice.