Breathlessness: causes, when to worry and how to manage it

Breathlessness has many possible causes, which is why it is assessed rather than guessed at. The NHS says shortness of breath has lots of different causes, and that you should not try to self-diagnose the reason. Instead, see a GP.

The NHS names asthma, a chest infection, being overweight, smoking and a panic attack as common causes. It adds that sometimes breathlessness can signal something more serious, such as chronic obstructive pulmonary disease (COPD), scarring of the lungs known as idiopathic pulmonary fibrosis, heart failure or lung cancer. Asthma + Lung UK gives a similar list of the most common causes: lung conditions such as COPD, heart conditions, anxiety, being overweight and smoking. It also lists allergic reactions, anaemia and complications of diabetes among other causes.

NICE Clinical Knowledge Summaries (CKS), the guidance written for GPs, groups causes by organ. It lists cardiac causes (silent heart attack, an irregular heart rhythm, fluid on the lungs and chronic heart failure), pulmonary causes (asthma, COPD, pneumonia, pulmonary embolism, lung cancer and fluid around the lung) and other common causes (anaemia, pressure on the diaphragm from fluid in the abdomen, obesity or pregnancy, and psychogenic breathlessness).

The NHS says it is common to feel out of breath in pregnancy, especially as your baby grows. NICE CKS also lists pregnancy among the situations in which the diaphragm is pushed upwards (diaphragmatic splinting), which can make breathing feel harder.

The NHS is clear about the warning signs, though. Breathlessness that comes on suddenly, breathlessness when you are lying down, or breathlessness together with other symptoms such as chest pain or dizziness needs to be checked immediately. The NHS includes breathlessness in its list of pregnancy symptoms that need help, so contact your midwife, maternity unit or NHS 111 rather than waiting for your next routine appointment.

Anaemia is another cause named by NICE CKS and Asthma + Lung UK, and it is something your midwife can check with a blood test. See our page on anaemia in pregnancy for more.

Asthma + Lung UK explains that breathlessness is not just physical, it is also a feeling that affects the way we think and act, and that each person feels it differently. You may feel hot, panicky or overwhelmed. Your chest may feel so tight that you cannot breathe in properly, you may feel you are suffocating and need to take deep breaths but cannot, or you may feel that breathing is very hard work and exhausting.

It describes two broad patterns. Chronic breathlessness develops gradually and can last for weeks, months or years, and some people also cough, bring up phlegm or feel wheezy. Acute breathlessness comes on suddenly and unexpectedly and needs to be tested or treated straight away, as it can be a sign of a new medical condition. NICE CKS uses the speed of onset in a similar way: acute (minutes), subacute (hours or days) and chronic (weeks or months).

Getting out of breath can be frightening, and Asthma + Lung UK notes that anxiety can in turn make you feel more breathless: as we become more anxious we may become more aware of our breathing, breathe faster and tense our breathing muscles, which can lead to a panic attack.

The NHS sets out three levels of action. Because breathlessness can be an emergency, it is worth knowing them in advance.

• Call 999 or go to A&E immediately if you have severe difficulty breathing (gasping, choking or not able to get words out), your chest feels tight or heavy, you have pain that spreads to your arms, back, neck and jaw, your lips or skin are turning very pale, blue or grey, or you feel suddenly confused. Do not drive yourself; ask someone to drive you or call 999.

• Call 999 or go to A&E if your child has difficulty breathing (they may make grunting noises or suck their stomach in under their ribcage), has lips or skin turning pale, blue or grey, is suddenly confused, or is limp, floppy or not responding as they normally do.

• Contact NHS 111 if you are more short of breath than usual, feel or are being sick, are coughing up blood, have pain or swelling in 1 leg, or have heart palpitations.

• See a GP if your shortness of breath gets worse when you are doing your normal activities or when you lie down, if you are short of breath and have swollen ankles, or if you have been coughing for 3 weeks or more. The NHS adds that you are not wasting anyone's time by getting it checked.

NICE CKS says an initial airway, breathing and circulation assessment is used to decide whether emergency admission is needed, with blood pressure, pulse, respiratory rate, temperature, level of consciousness and oxygen saturation checked. For people who do not need emergency admission, a medical history is taken, heart, lung and nerve examinations are carried out and appropriate investigations are arranged. It lists features that would lead to emergency admission, including rapid onset or worsening of suspected heart failure, anaphylaxis, suspected sepsis, an ECG suggesting arrhythmia or a heart attack, and features of a severe asthma attack or COPD flare-up.

Asthma + Lung UK says a GP will first ask about your medical history, smoking history and body mass index (BMI), and may then arrange tests such as an electrocardiogram (ECG), a chest X-ray, spirometry (a breathing test) and FeNO (fractional exhaled nitric oxide, a test used for airway inflammation).

Your doctor may also ask you to describe your breathlessness using the Medical Research Council (MRC) breathlessness scale. Asthma + Lung UK explains that this scale grades what breathlessness stops you doing, from grade 0 (only breathless with strenuous exercise) to grade 4 (too breathless to leave the house, or breathless when dressing or undressing).

Treatment depends on the cause. Asthma + Lung UK says you may be prescribed medicines, or referred for services such as pulmonary rehabilitation to help improve your breathing muscle strength. NICE CKS says that when emergency admission is not needed, the underlying cause is managed and investigations are arranged to identify or confirm it.

Asthma + Lung UK also notes that lung function tests and scans do not always show how breathless you feel, because the way you breathe, your lifestyle, and how you think and feel about your breathing also matter. That is why breathing techniques and staying active are part of care alongside medicines.

Asthma + Lung UK recommends practising breathing control when you are sitting, relaxed and not out of breath, so that you can use it when you are breathless or anxious. Ask a physiotherapist or healthcare professional which techniques suit you.

• Relaxed breathing: with one hand on your chest and the other on your tummy, breathe in slowly through your nose and let your tummy move out; breathe out through your mouth, taking longer to breathe out than in.

• Pursed-lips breathing: breathe in gently through your nose, then breathe out through pursed lips as if blowing out a candle, for as long as is comfortable, without forcing your lungs to empty.

• "Blow as you go": breathe in before you make an effort, such as lifting a heavy bag, and breathe out while you make the effort.

• Paced breathing: count in time with your steps while being active, which helps avoid breath holding.

• Recovery positions: sitting leaning forward with your elbows on your knees, leaning back against a wall, leaning forward at a table with your head and arms on pillows, or lying on your side with pillows under your head and shoulders.

• A handheld battery fan held about 6 inches from your face can help you feel less breathless.

Asthma + Lung UK stresses that keeping active matters. If you avoid activity that makes you out of breath, your muscles get weaker and need more oxygen to work, which makes breathlessness worse. With regular exercise you need to breathe less to do the same activity.

It also suggests planning your day and pacing yourself, breaking tasks into smaller ones, keeping frequently used items within easy reach, wearing loose clothes that are easy to put on and take off, using a towelling robe after a shower instead of drying with a towel, and asking for support when you need it. Singing or playing a musical instrument can help you control your breathing, and eating a well-balanced diet supports your overall health.

On the NHS, breathlessness is usually assessed first by a GP, who may arrange blood tests, a chest X-ray, an ECG or breathing tests locally and refer you to a respiratory or heart clinic if needed. If it is sudden or severe, urgent care through 111, 999 or A&E is the route.

Some people choose a private consultation or private diagnostic tests for quicker access. The tests and the reasons for doing them are the same in either setting, and the findings should be shared with your GP so your records stay complete.