Chest
Shortness of breath
A feeling of not being able to get enough air, breathing faster or harder than normal, or struggling for breath — which ranges from a normal response to exertion to a sign of serious heart or lung problems, and which when sudden and severe is a medical emergency.
Education and reference only. This explains the common causes of shortness of breath and the warning signs that need urgent help, in plain language — it is not a diagnosis or a substitute for advice from a clinician. If you feel very unwell or are worried, seek medical help.
Quick answer
What is shortness of breath?
Breathlessness is the uncomfortable awareness that breathing is taking more effort than it should. It is normal to be breathless after hard exercise, but breathlessness that comes on with little or no exertion, that wakes you at night, or that has appeared suddenly is not normal and needs attention.
- Get urgent help: Call 999 for sudden, severe breathlessness, or breathlessness so bad you cannot speak in full sentences. Call 999 if breathlessness comes with chest pain, sweating or pain spreading to the arm or jaw — this may be a heart attack.
- Self-care: If your breathlessness has been investigated and has a known long-term cause, the most important step is to follow the management plan your clinician has given you and to use any prescribed inhalers or treatments exactly as advised.
About shortness of breath
Breathlessness is the uncomfortable awareness that breathing is taking more effort than it should. It is normal to be breathless after hard exercise, but breathlessness that comes on with little or no exertion, that wakes you at night, or that has appeared suddenly is not normal and needs attention. The lungs and the heart are the two systems most often responsible: the lungs because conditions such as asthma, chronic obstructive pulmonary disease and infections narrow the airways or fill them with fluid or mucus, and the heart because a weak heart allows fluid to back up into the lungs. Anaemia reduces the blood's ability to carry oxygen and so causes breathlessness on effort, while anxiety can cause genuine breathlessness through rapid, shallow over-breathing. The speed of onset is the key clue: sudden, severe breathlessness can mean a clot on the lung, a collapsed lung or a heart attack and must be treated as an emergency.
When to get help
Call 999 or go to A&E if shortness of breath comes with any of these warning signs:
- Call 999 for sudden, severe breathlessness, or breathlessness so bad you cannot speak in full sentences.
- Call 999 if breathlessness comes with chest pain, sweating or pain spreading to the arm or jaw — this may be a heart attack.
- Call 999 for sudden breathlessness with a sharp chest pain or coughing up blood — this can be a clot on the lung.
- Call 999 if your lips or face turn blue or grey, or if you become confused or drowsy.
- Seek urgent help if you are gasping after a bee sting, new food or medicine, with swelling of the lips, tongue or throat.
When to see a doctor
Sudden or severe breathlessness is an emergency — call 999. Get urgent help if breathlessness comes on with chest pain, blueness of the lips, or after a possible allergic trigger. Arrange a prompt appointment if you have become breathless on everyday tasks such as climbing stairs, if you are waking at night fighting for breath, if your ankles are swelling, or if a known lung condition is flaring beyond your usual self-management. Gradually worsening breathlessness over weeks or months always deserves assessment to find the cause.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
What can cause it
Common causes of shortness of breath
Shortness of breath has many possible causes. Each links to a full, plain-language guide to that condition — what it is, how it's treated and when to seek help.
What helps
Self-care and what you can do
If your breathlessness has been investigated and has a known long-term cause, the most important step is to follow the management plan your clinician has given you and to use any prescribed inhalers or treatments exactly as advised. Stopping smoking is the single most valuable thing you can do for your lungs, and staying as active as your condition allows helps maintain your breathing capacity. Controlled breathing techniques — breathing slowly through pursed lips or using a relaxed, low-and-slow pattern — can ease the sensation during a flare. Keep your home well ventilated, avoid known triggers such as smoke and cold air, and keep vaccinations up to date to reduce chest infections.
Answers
Shortness of breath: frequently asked questions
When is breathlessness an emergency?
Call 999 if breathlessness comes on suddenly and severely, if you cannot speak in full sentences, if it comes with chest pain or blue lips, or if it follows a possible allergic reaction with facial or throat swelling.
Why am I breathless when lying flat or at night?
Breathlessness that is worse lying down, or that wakes you a few hours into sleep, can be a sign that fluid is backing up into the lungs, as happens in heart failure. This pattern should always be checked by a doctor.
Can anxiety cause real shortness of breath?
Yes. Anxiety and panic cause fast, shallow over-breathing that produces a genuine feeling of breathlessness. However, this should only be accepted as the cause after the heart and lungs have been checked.
I get breathless on stairs but feel fine resting — is that normal?
New breathlessness on exertion that is not explained by being unfit or unwell is worth investigating, as it can be an early sign of a heart, lung or blood problem such as anaemia. Book a routine appointment to have it assessed.
Sources
Where this is drawn from
- NICE CKS: Breathlessness.
- Asthma + Lung UK: breathlessness.
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