What is severe asthma?

Learn about severe asthma and the treatments available

Health advice > Severe asthma  

What is severe asthma?

Someone with ‘severe asthma’ has a specific type of asthma which doesn’t get better with the usual medicines.

Even if someone takes those medicines exactly as prescribed, a different approach is needed to control symptoms and reduce frequent asthma attacks.

Other causes and triggers for the symptoms have also been ruled out as much as possible.

Around 4 out of 100 people with asthma have severe asthma, which is about 200,000 people in the UK. 

If your GP or asthma nurse suspects you have severe asthma they may refer you to an asthma specialist clinic for an in depth assessment. 

Your GP or asthma nurse will continue to look after your asthma while you are waiting to see the specialist team and will continue to share responsibility for your care even when you are seeing them.

“We don’t understand yet why some people get asthma and some people get severe asthma,” says Dr Andy Whittamore, Asthma + Lung UK's in-house GP.

“We know that each individual with asthma can have different triggers and a different chemical reaction in their airways.

“That’s why Asthma + Lung UK is supporting research looking into what goes on in the body to cause severe asthma, and what makes it so much harder to control with the usual asthma medicines.” 

What’s different about severe asthma?

Severe asthma is the most serious and life-threatening form of asthma. Most people with asthma can manage their symptoms well with the usual medicines like a preventer inhaler and a reliever inhaler

But someone with severe asthma struggles to manage their symptoms even with high doses of medicines.

And sometimes it can take a while to find a combination of medicines and doses that works best for you.

Even if your asthma is difficult to control, it’s not the same as severe asthma. If you have difficult to control asthma you should be able to get on top of your symptoms with support from your GP or asthma nurse, with an action plan, regular reviews and a good routine of taking your asthma medicines. 

Who gets severe asthma?

Severe asthma affects both adults and children. It can develop at any age. Most people who are diagnosed with severe asthma already have an asthma diagnosis: perhaps their asthma changed over time, or developed into severe asthma because of hormonal changes, or pneumonia for example. 

Some people are diagnosed right away with severe asthma, but it’s likely that they had asthma for some time before without it being diagnosed as severe. And it can take time to get a diagnosis of severe asthma.

 I was diagnosed with asthma at 35, but my GP said I’ve probably always had it. I spent a lot of time in hospital with chest infections and croup as a child. In the lead-up to my severe asthma diagnosis, aged 40, I had pneumonia and started getting a lot of infections. My asthma changed and I could barely walk or move.

 – Kate

What is it like to have severe asthma?

Severe asthma is an unpredictable condition and it’s different for everyone. So, it’s hard to describe exactly what it’s like to have severe asthma.

But people with severe asthma have more asthma attacks than people with mild or moderate asthma, they are more likely to have to stay in hospital and they are more likely to be on long term steroid tablets. 

The symptoms, triggers, responses to medicines, energy levels and impact on daily life are unique to each individual, plus they can change over time. 

Having severe asthma can be tough. But with the right support and treatment you can hopefully feel more confident about managing your symptoms and getting on with your life.

Read real life stories of people living with severe asthma.  

Outlook for people with severe asthma

“Because severe asthma is so unpredictable in the treatments it responds to, and the course it takes, the long-term outlook is different for everyone,” says Dr Andy.

“There are lots of treatments around for people with severe asthma and your team of healthcare professionals will work with you to find the right ones for you so you can have the best quality of life possible in the long term.”

Airway remodelling

One of the possible long-term effects of severe asthma is something called ‘airway remodelling’.

This is where your airways become thicker over time, so the airway itself is narrower, making it harder to breathe.

Airway remodelling can happen if people have frequent asthma attacks. If you have severe asthma, your risk increases because you’ll probably have asthma attacks more often. Long-term exposure to pollutants including tobacco smoke can play a part too. 

Whatever the reason, if you’re continually having lots of symptoms over a long period of time then there’s a risk your airways will become permanently narrowed, scarred and inflamed, which can mean your symptoms get worse. 

For most people, changes to the structure of your airways can be avoided with good asthma management. 

Airway remodelling can be treated with bronchial thermoplasty, but this treatment is not recommended for everyone with severe asthma.

COPD and Asthma-COPD overlap syndrome

Long term severe asthma can sometimes lead to a chronic lung condition called COPD (chronic obstructive pulmonary disease) or ACO (asthma-COPD overlap).

Many people with COPD and Asthma-COPD overlap syndrome are given physiotherapy and exercises called Pulmonary Rehabilitation.

Pulmonary rehabilitation has been shown to help people with severe asthma with their breathing and quality of life.

Latest Treatments for severe asthma

In recent years a new type of treatment has been developed using monoclonal antibodies, known as mAbs or biologics therapies.

These treatments can dramatically improve the lives of people with certain types of severe asthma and can cut down the dose of steroids they are taking and lead to a better quality of life.


Last updated March 2020

Next review due October 2022

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