Expert reviewer, Dr Richard Russell, Consultant Chest Physician
Next review due January 2021

Asthma is a common, long-term condition that affects your airways leading to your lungs. It can make you cough, wheeze and feel short of breath.

It's common to develop asthma as a child, but it can start at any age. Over five million people in the UK have asthma, including over one million children.

Most people who have asthma will have it for life – there's no cure. But taking your asthma medicines and avoiding particular triggers will help to keep it under control.

About asthma

Asthma affects your airways – the tubes that carry air in and out of your lungs. It makes your airways become inflamed and more sensitive to specific triggers.

There are many different trigger factors that can make your asthma symptoms flare up. These may include:

  • respiratory infections – such as a cold or flu
  • allergies to pollen, animals (commonly cats, dogs and horses), house dust mites or certain foods
  • air pollution – from traffic fumes, cigarette smoke or dust
  • exercise, especially in cold or dry environments
  • emotions – laughing, anger or stress
  • changes in the weather – especially changing temperatures
  • certain medicines, such as aspirin and beta-blockers

When you're exposed to these trigger factors, muscles around your airways constrict causing them to tighten. Your airways become inflamed, and may become blocked with sticky mucus and phlegm. This makes it more difficult for air to flow in and out of your lungs, meaning it gets harder to breathe. 

Symptoms of asthma

Symptoms of asthma include:

  • coughing
  • wheezing
  • finding it difficult to breathe
  • tightness in your chest

Which symptoms you have, and how severe they are, vary from person to person. You may not have all the symptoms listed above, but you'll have at least a couple if you have asthma. If you have these symptoms, see your GP.

You may find that your symptoms are worse at night, or early in the morning. They may flare up at times and can completely disappear at other times. They may have specific triggers, such as pollen or being around certain types of animal (for example cats, dogs or horses). See our About section above for more information on asthma triggers.

When your symptoms flare up suddenly, this is called an ‘asthma attack’. If you're having an asthma attack, you may find that you're struggling to talk or breathe. You need to seek help urgently. See our section below on What to do if you have an asthma attack, for more information. 

Diagnosis of asthma

There's no one single test that can be used to diagnose asthma. But there are a number of tests that can give doctors a good idea of how likely you are to have it. Your GP or specialist will make a diagnosis based on your symptoms and history, and the results of any tests you have.

Seeing your GP

When you first see your GP, they'll want to find out about your symptoms. They may ask you what time of day your symptoms tend to flare up, or if you notice any difference throughout the year. They'll also want to know if there's anything in particular that makes your symptoms worse, such as exercise or cold air. They may ask whether you’re prone to allergies or have a family history of asthma and allergies. If you've developed symptoms as an adult, your GP will also want to know if your symptoms seem to be related to your work.

Your GP may use a stethoscope to listen to your chest to see whether they can hear any wheezing sounds. Sometimes it’s possible to hear the wheezing without a stethoscope.

Tests for asthma

If your GP thinks that you may have asthma, they may also ask you to have one or more of the following tests.

  • Spirometry – this test measures how much air you can breathe out after you have fully inhaled.
  • Bronchodilator reversibility – this involves taking asthma medication to see if it improves your spirometry test.
  • Peak flow variability – this test measures how fast you can blow air out of your lungs in one hard blow. You may be asked to perform this test every morning and evening, over two to four weeks, to show how your airflow may vary.
  • A FeNO (fractional exhaled nitric oxide) test – this measures the amount of gas (nitric oxide) in your breath. The level of nitric oxide can be higher in people with asthma.

New guidelines for doctors about asthma were published in November 2017. These recommend that all adults and children over the age of five with symptoms of asthma should have one or more of these tests. It takes time for new guidelines to be put into practice though, so it will depend on services in your area as to what tests you’re offered.

Tests for asthma don't tend to work well in children under five. If your child is under five, your GP is likely to treat their symptoms based on what they have observed, rather than carrying out any tests. If your child still has symptoms once they reach five, they may then be offered tests for asthma. 

Self-help for asthma

Your doctor should give you some advice and information about managing your asthma as soon as you've been diagnosed. This should include things like how to recognise if you're having an asthma attack, how to monitor your own treatment and advice about avoiding triggers. Some common triggers (such as the weather) can’t be avoided, but you may be able to avoid other triggers (such as being around pets).

Your doctor might ask you to keep an eye on your asthma yourself, by measuring your peak flow at home using a peak flow meter.

There are certain things you may be able to do to improve your symptoms.

  • Stopping smoking. This is good for your overall health and will also improve your asthma symptoms. If you take a preventer inhaler, smoking can reduce its effectiveness.
  • Losing excess weight. If you're overweight, losing the excess might help to reduce your symptoms.
  • Breathing exercises. These may help to control your asthma symptoms. In some situations, your GP may be able to refer you to a respiratory physiotherapist, who can help with your breathing.
  • Taking regular exercise. If your asthma is under control, you shouldn't be afraid to take part in regular exercise. As well as generally being good for your health, exercise can improve how well your lungs work – which may help to reduce your symptoms. 

Treatment of asthma

Treatment for asthma involves taking medicines to control your symptoms. You usually take the medicines through inhalers – devices that deliver the medicines straight to your airways as you breathe in. The aim of treatment is for you to be able to live a completely normal life. This means no symptoms during the day, no waking up due to asthma, no asthma attacks and no limitations on activities you can do.

There are two basic types of inhaler medicines for asthma:

  • relievers – to treat your symptoms as soon as they occur (these are usually coloured blue)
  • preventers – that you take daily to help prevent your symptoms (often brown, but the colour can vary)

Your GP or nurse should provide you with a personalised asthma action plan. This will give some written information about how and when you should use your asthma medicines, as well as what to do if your asthma is worsening.

Reliever inhalers

Reliever inhalers are also called bronchodilators. You should use this if your symptoms flare up. A reliever quickly eases your asthma symptoms by helping to relax and widen your airways. It contains medicines such as salbutamol (eg Ventolin) and terbutaline (eg Bricanyl).

Everyone with asthma should have a reliever inhaler. It's important to check that your reliever inhaler is in date. For some people, the reliever inhaler will be all they need. If you need to use your reliever more than twice a week, or your asthma is worse at night, you should contact your GP surgery. Your asthma nurse or GP may then suggest you use a preventer medication.

Preventer inhalers

Your doctor may also prescribe you a preventer inhaler if your reliever isn't enough to control your symptoms. If you’re prescribed a preventer inhaler, you should use it every day, even if you don’t have asthma symptoms. The protective effect builds up over time.

Preventers usually contain a corticosteroid medicine, such as beclometasone (eg Qvar) or fluticasone (eg Flixotide). These work by reducing the inflammation of your airways. It can take up to seven days for preventer medicines to work. Once they start working, you may not need to use your reliever inhaler at all.

Additional therapy

Sometimes the standard reliever and preventer inhalers may not be enough to control your asthma. Your doctor may then suggest trying other medication. These may include the following.

  • A leukotriene receptor antagonist, such as montelukast (eg Singulair). Your doctor may suggest trying this for four to eight weeks to see how you get on with it.
  • A long-acting reliever, such as salmeterol (eg Serevent) or formoterol (eg Oxis). These work in a similar way to a short-acting reliever but their effects last for up to 12 hours. You may be prescribed a long-acting reliever and corticosteroid in one inhaler.
  • A long-acting muscarinic receptor antagonist (LAMA) such as tiotropium bromide (eg Spiriva Respimat).
  • A drug called omalizumab (Xolair). This is a type of medicine called a monoclonal antibody, which works to reduce the effects of your immune system. Your doctor may prescribe it if you have severe asthma and other treatments aren't working.
  • Steroid tablets. These might be prescribed if your asthma still isn't under control after trying other treatments. Your GP will need to refer you to a specialist for this.

Inhalers, spacers and nebulisers


There are many types of inhalers and they all work slightly differently. The most common ones are pressurised metered-dose inhalers, which are plastic devices with a mouthpiece, and a pressurised can containing the medication. Metered-dose inhalers can be difficult to use, especially for children and older people. If you do find it difficult, your GP may suggest you try a spacer with your inhaler, or prescribe a dry powder inhaler or a breath-activated inhaler instead.

Using your inhaler correctly is essential to control your asthma. Watch our animation in the section below to see how to use a metered-dose inhaler. Your GP, nurse or pharmacist should also show you how to use it. If you have any questions about how to use your inhaler, it's important to ask.


Your doctor or nurse may suggest you or your child use a spacer with your inhaler. A spacer is a plastic cylinder that you attach to the end of your inhaler. You activate the inhaler and then breathe in through the mouthpiece on the spacer. Having a spacer means you don't need to be able to coordinate your breathing with activating the inhaler, making the whole thing easier to do.

Spacers can be helpful if you're finding it hard to get the technique of using an inhaler on its own. They're also particularly useful for children and people who need to take high doses of medication. Babies and very young children can use a spacer with a face mask if they can’t use the mouthpiece. You'll need to keep your spacer clean by washing it once a month in mild detergent.


A nebuliser is a device that converts your asthma medications into an aerosol that you breathe in. They can help to deliver more of the medicine to exactly where it’s needed. Most people won't need to take a nebuliser. You may be given one if you have a severe asthma attack and you need emergency treatment. They can also sometimes be used in people who have severe asthma, and who are unable to use other devices.

Monitoring your treatment

You'll usually be asked for a review with your GP or specialist doctor once a year. Your doctor will want to know how you're getting on with your medication. They'll ask you if you've had any problems using your inhaler, and if you've had any flare-ups when you've had to use your reliever inhaler. They will usually also want a test to check your lung function, such as a spirometry or peak flow test. If you're having problems keeping your asthma under control and you're not due a review, make an appointment to see your GP.

If your asthma has been well-controlled for some time, your doctor may suggest gradually reducing the amount of medicines you take. They'll only suggest this if you're no longer getting any asthma symptoms, and you'll have a chance to discuss this with your doctor first. Your doctor will monitor you and ask you to come for a review after reducing your medicines. 

How to use your metered-dose inhaler

What to do if you have an asthma attack

An asthma attack is a sudden flare-up of your symptoms. You need to seek help for an asthma attack straightaway.

You’re having an asthma attack if:

  • your symptoms are getting worse (cough, breathlessness, wheezing or tight chest)
  • you’re too breathless to speak, eat or sleep
  • your breathing is getting faster and you can't catch your breath
  • you're reliever isn't helping, or isn't lasting more than four hours

If you have an asthma attack, try to stay calm and take the following steps.

  • Take four puffs of your reliever inhaler immediately. If possible, use a spacer.
  • If your symptoms don’t get better, take two puffs of your inhaler every two minutes. You can take up to 10 puffs until your symptoms go away.
  • If your symptoms don’t go away, you should call an ambulance.
  • If you go to hospital, take your asthma treatments and, if possible, your personalised asthma plan with you.

If your symptoms improve and you don’t need to call an ambulance, you still need to see your GP or asthma nurse within 48 hours. They may need to review your treatment.

Causes of asthma

Asthma is caused by a combination of different factors. There is a genetic link – people with asthma often have a family history of the condition. It's also linked to other allergy-related conditions, such as eczema and hay fever. It's common to have more than one of these conditions yourself, or in your family. Having one of these conditions, such as hay fever doesn't mean that you’ll necessarily get asthma though.

It's thought that having a respiratory virus as a baby may increase your risk of developing asthma, if you're already prone to the condition. Smoking during pregnancy will also increase the risk of your baby developing asthma. If you smoke around babies and children, they're more likely to get asthma as well.

You may develop occupational asthma if you work with particular chemicals and other substances such as flour dust, substances in paint and industrial materials. If you have occupational asthma, you may notice that your symptoms are better on holidays or days away from work. It's important that you discuss this with your GP.

Frequently asked questions

  • Breastfeeding has many health benefits for your baby, but it doesn't seem to have a significant effect on the risk of your baby developing asthma.

    More information

    Breastfeeding your baby has many health benefits. It may help to reduce the risk of your baby developing many health conditions, including ear infections, stomach upsets and respiratory infections. Some studies have found a weak link between breastfeeding and a reduced risk of developing asthma. But any reductions in risk have been found to be very small and not big enough to be significant.

    Health authorities recommend breastfeeding is the best option for feeding your baby for the first six months of their life. This is for a number of reasons, including health benefits for you, your baby and helping to strengthen your bond with your baby. If you have any questions or concerns about breastfeeding, talk to your midwife or health visitor. 

  • Yes, some children who have asthma will grow out of it by the time they’re adults. But others continue to have symptoms throughout their life.

    More information

    Asthma symptoms often improve as children get older. Children under two who are diagnosed with asthma tend to grow out of their symptoms by the time they're 11.

    Children who have severe asthma or more frequent symptoms, and those who have other allergies are less likely to grow out of their asthma. Whether or not you grow out of your symptoms, learning how to manage your asthma and getting into a good routine with taking treatments means you should be able to live a normal, active life. 

  • Yes, being around people who smoke can increase the risk of asthma in children.

    More information

    Passive smoking is when you breathe in other people’s second-hand tobacco smoke. Babies and children take more smoke into their lungs than adults, and as their lungs are still developing, they're at greater risk from the toxins in smoke.

    Babies and young children are at greater risk of developing asthma if they're exposed to tobacco smoke. For children who already have asthma, passive smoking can trigger a flare-up in their symptoms (an asthma attack).

    It’s best that all children – whether they have asthma or not – are kept away from smoky environments. If you have children or are pregnant and smoke, consider quitting. Your GP can give you support and advice on how to stop smoking.

  • Cough-variant asthma is a type of asthma where your main symptom is coughing. You don't have the other usual symptoms of asthma, such as wheezing.

    More information

    Wheezing is one of the most recognisable symptoms of asthma. But some people can have asthma without any wheezing – instead, their main symptom is a dry cough. This tends to be worse at night. This type of asthma is called cough-variant asthma.

    The treatment for cough-variant asthma is the same as for regular asthma. Your child will be prescribed a short-acting reliever inhaler, such as salbutamol (eg Ventolin), and/or an inhaled corticosteroid preventer, such as beclometasone (eg Asmabec). Some people with cough-variant asthma eventually develop regular asthma, but taking corticosteroid medicines is thought to reduce the risk of this.

    If you have any questions or concerns about your child's diagnosis, talk to your GP.

  • During pregnancy, your asthma may get better, get worse or stay the same. As long as your asthma is well-controlled though, it shouldn't have any important effects on your pregnancy, labour or your baby.

    It's particularly important to continue taking your asthma medicines as usual if you're pregnant, to maintain good control of your asthma. Asthma medicines are safe to take during your pregnancy and after you've had your baby, if you're breastfeeding. You and your baby are at greater risk of complications if you don’t take your usual medicines and your asthma isn't properly controlled.

    You'll be closely monitored throughout your pregnancy to make sure your symptoms are well-controlled, even if you’re not having any problems. If you've got any concerns about your asthma during your pregnancy, talk to your GP.

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  • Reviewed by Pippa Coulter, Freelance Health Editor, Bupa Health Content Team, January 2018
    Expert reviewer, Dr Richard Russell, Consultant Chest Physician
    Next review due January 2021