Diagnosing the cause of breathlessness

On this page, we explain how the cause of breathlessness is diagnosed. It includes information on what will happen when you see your doctor, the questions they might ask, tests they’ll do and how long it will take to get a diagnosis.

Breathlessness is often dismissed as a normal part of ageing, so people don’t tell their doctor. Some people feel responsible for causing their illness and don’t feel they deserve help. While others don’t realise they can get any help for their breathlessness. But getting a diagnosis is very important. If you know what’s causing your breathlessness, you can find out what can help. The earlier you get a diagnosis, the better. And you may feel less anxious once you have a diagnosis.

Use our online breath test to find out if your breathlessness is something to get checked out with your doctor.

What will happen when I see my doctor?

You may not actually feel out of breath when you see your doctor - you’ll be sitting down and may have only walked a short distance. So, think about how you’ll describe your breathlessness. If you’d find it useful, you could bring someone with you who can help describe your breathlessness.

Your doctor should show you the MRC breathlessness scale to help describe how breathless you get.

The MRC breathlessness scale

The scale health care professionals usually use to measure breathlessness is the Medical Research Council (MRC) breathlessness scale. This does not recognise other aspects of breathlessness – such as how you think or feel about getting out of breath.

The MRC scale shows what your breathlessness stops you doing. Your grade is the one that describes you when you’re at your best.

Grade Degree of breathlessness related to activities
1 Not troubled by breathlessness except on strenuous exercise
2 Short of breath when hurrying on the level or walking up a slight hill
3 Walks slower than most people on the level, stops after a mile or so, or stops after 15 minutes walking at own pace
4 Stops for breath after walking about 100 yards or after a few minutes on level ground
5 Too breathless to leave the house, or breathless when undressing

It’s also important to tell the doctor:

  • what you used to be able to do that you can’t do any more
  • what people of your age around you do that you find difficult
  • what your personal goals are for your day-to-day activity

You might find it useful to use local landmarks such as bus stops, shops and hills to help you describe these things.

If you have a phone with a camera, you could record the sort of activities that make you out of breath so you can show your doctor what it looks or sounds like.

What questions will my doctor ask?

These are the sort of questions your doctor may ask:

  • How long have you been feeling breathless and how quickly did it come on?
  • Does it come and go or is it there all the time?
  • Is there any pattern to your breathlessness?
  • Does it start or get worse at any particular time of day?
  • Does it come on or get worse when you lie flat?
  • Does anything bring it on? For example, pollen, pets or medication?
  • Do you smoke?
  • Do you also have a cough or bring up phlegm?
  • Do you get chest pain, palpitations or ankle swelling?
  • How active are you usually? Don’t forget everyday activities, such as walking or DIY.
  • What’s your job or occupation (both current and previous)?
  • Is your breathlessness related to certain times at work?
  • Do you have a history of heart, lung or thyroid disease, or of anaemia?
  • Do you have any family history of breathlessness?
  • Have you made any changes in your life because of your shortness of breath?
  • Do you feel worried, frightened, depressed or hopeless?
  • What have you done to help you cope with the way you’re feeling?

Your answers are important because they will help your doctor to understand what’s causing your breathlessness. It would be a good idea to take your answers to these questions with you to your doctor’s appointment.

What tests will my doctor do?

Your doctor is likely to do some tests to help diagnose what’s causing your breathlessness.

They may:

  • do some breathing and lung function tests
  • check the number of breaths you take every minute, listen to your chest, and look and feel how your chest moves as you breathe
  • check your heart rate and rhythm, and check if fluid is building up in your ankles or lungs
  • check your blood pressure and temperature
  • check your height, weight, waist and body mass index
  • examine your head, neck and armpits to see if your lymph glands are swollen
  • look at your eyes, nails, skin and joints
  • check your blood oxygen levels with a pulse oximeter

If your doctor spots signs that you’re anxious or depressed, they may also ask you to do a short questionnaire.

You might be referred for more tests at your GP surgery, a local testing centre or hospital. For example:

  • a chest X-ray
  • a spirometry test
  • an electrocardiogram or ECG - if your breathlessness is intermittent, you might be asked to wear a portable recorder for 24 hours or seven days to record your heart’s electrical activity
  • an echocardiogram - this is a non-invasive ultrasound of your heart which can tell how well it’s working
  • blood tests to detect anaemia, allergies or any thyroid, liver, kidney or heart problems.

How long will it take to get a diagnosis?

Getting a diagnosis for the cause of long-term breathlessness can take some time. Your health care professional must consider all possible causes. You may need to take repeated tests and try various treatments before the cause is identified.

Next: Treating breathlessness

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