How is severe asthma diagnosed?

It can take time to get a severe asthma diagnosis

Just as there’s no one-off test to diagnose asthma instantly, there’s no single test to find out if the kind of asthma you have is severe asthma. This means it can take time to get a diagnosis. The process and length of time will vary from person to person.

Why can severe asthma be so difficult to diagnose?

It’s worth remembering that while around 17 per cent of people with asthma have difficulty breathing most of the time, often needing to use their reliever inhaler (usually blue) and experiencing frequent asthma attacks,­ only around five per cent of people with asthma have what’s medically classed as ‘severe asthma’.

The rest (the other 12 per cent) have what's called difficult to control asthma. Although it can take time to make sure you’ve the right support from your GP or asthma nurse, and to find the right combination of medicine that works for you, this type of asthma can be well managed.

But if you have severe asthma, your symptoms may only improve to a certain extent with the usual treatments, even if you do take them correctly and exactly as prescribed. The challenge for you and your healthcare professionals is to find out which type of asthma you have. Once you know, you can then work together to find the mix of treatments that works best for you.

What are the signs that mean you might have severe asthma?

If you’ve been diagnosed with asthma and you’ve tried all the usual asthma treatments, but your symptoms haven’t improved, your GP or asthma nurse will want to know a number of things, including whether you:

  • have symptoms all the time
  • find it hard to be physically active – especially if that means you struggle to do everyday things such as climb the stairs or play with your children
  • have frequent asthma attacks
  • have frequent night-time symptoms

If you do and you’re taking your asthma medicines exactly as prescribed using the correct inhaler technique, your GP is likely to send you to a specialist asthma clinic or centre for a consultation.

Who will you see at the specialist asthma clinic?

If you’re referred for a specialist appointment, it will depend on the set-up at the clinic or centre and your own individual needs as to which healthcare professionals you will see. Your support team might include a severe asthma specialist, an asthma nurse specialist, a physiotherapist, a clinical psychologist, a physiologist, a pharmacist, a dietician and/or an allergist. If you smoke, you might have the chance to see a smoking cessation adviser. If your asthma means you can’t work, you might be able to talk to someone about benefits.

What happens at your first appointment at the specialist asthma clinic?

The aim of your first appointment is to get the ball rolling for you and for your healthcare professional to work out if you have severe asthma. You will probably need to answer questions you’ve answered before with your GP. If you feel confused or frustrated that you’re going over the same things again, try to remember that your new clinic needs to gather a complete picture to fully understand your individual needs.

Your asthma consultant will need to know about you - your medical history and your lifestyle. They will also need to know all about your asthma, including a list of the medicines you’re taking, the doses, and how you’re taking them, how your asthma’s been and what kind of things usually trigger it. This is your chance to explain what impact asthma is having on your life and on your family.

The more open and honest you can be, the better chance you’ll have of getting the right diagnosis, support and treatments. So tell your healthcare professional if, for example, you’re struggling to take your medicines as prescribed or you’re getting unpleasant side effects from your current medicines.

You can find out more about preparing for this first appointment and follow-up appointments here.

What tests will you need to have?

You’ve probably already had various tests, such as blood tests and measurements of your height and weight, and some of the tests covered in detail on our tests for asthma page, including:

  • peak flow
  • spirometry
  • fractional exhaled nitric oxide (FeNO)
  • airways responsiveness 

If your consultant thinks you may have severe asthma, you may also be sent for some additional tests to help determine if your asthma is severe or if there are other factors involved. You can find a list of these tests – and the reasons why you might need them – here.

What will happen next?

Depending on which tests you need and when you have them, your healthcare professional might change the medicines or doses you’re taking at this first appointment, or they might wait and do that at a follow-up appointment.

If you’re taking your preventive steroid inhaler correctly but your symptoms still aren’t improving, you will probably be prescribed additional drugs in various doses and combinations to see if different levels and combinations work for you.

You’ll be given a diagnosis of severe asthma if your healthcare professional is sure that the usual asthma medicines aren’t able to keep your symptoms under control and that there are no other causes for your symptoms or triggers that can be treated.

If you’re diagnosed with severe asthma, you will typically need treatment with a high dose of inhaled corticosteroids plus a second drug such as a beta-2 agonist, leukotriene receptor antagonists or slow-release theophylline and/or oral corticosteroids to prevent it from becoming out of control.

But remember that severe asthma is so different for everyone and often so unpredictable that the combination of medicines and doses that are right for you will be very personal - and finding it may take time.

During this time you may:

And don’t forget you can call our friendly asthma nurses on 0300 222 5800 (9am – 5pm; Mon – Fri) to ask any questions you have about your new diagnosis.

Last updated November 2016

Next review due November 2019