Asthma is a common long-term condition that can cause coughing, wheezing, chest tightness and breathlessness.
The severity of these symptoms varies from person to person. Asthma can be controlled well in most people most of the time, although some people may have more persistent problems.
Occasionally, asthma symptoms can get gradually or suddenly worse. This is known as an ‘asthma attack’, although doctors sometimes use the term ‘exacerbation’.
Severe attacks may require hospital treatment and can be life threatening, although this is unusual.
Read more about the symptoms of asthma and diagnosing asthma
Asthma is caused by inflammation of the small tubes, called bronchi, which carry air in and out of the lungs. If you have asthma, the bronchi will be inflamed and more sensitive than normal.
When you come into contact with something that irritates your lungs – known as a trigger – your airways become narrow, the muscles around them tighten, and there is an increase in the production of sticky mucus (phlegm).
Common asthma triggers include:
Asthma may also be triggered by substances (allergens or chemicals) inhaled while at work. Speak to your GP if you think your symptoms are worse at work and get better on holiday.
The reason why some people develop asthma is not fully understood, although it is known that you are more likely to develop it if you have a family history of the condition.
Asthma can develop at any age, including in young children and elderly people.
Read more about the causes of asthma
In the UK, around 5.4 million people are currently receiving treatment for asthma.
That’s the equivalent of 1 in every 12 adults and 1 in every 11 children. Asthma in adults is more common in women than men.
While there is no cure for asthma, there are a number of treatments that can help control the condition.
Treatment is based on two important goals, which are:
For most people, this will involve the occasional – or, more commonly, daily – use of medications, usually taken using an inhaler. However, identifying and avoiding possible triggers is also important.
You should have a personal asthma action plan agreed with your doctor or nurse that includes information about the medicines you need to take, how to recognise when your symptoms are getting worse, and what steps to take when they do so.
Read more about treating asthma and living with asthma
For many people, asthma is a long-term condition – particularly if it first develops in adulthood.
Asthma symptoms are usually controllable and reversible with treatment, although some people with long-lasting asthma may develop permanent narrowing of their airways and more persistent problems.
For children diagnosed with asthma, the condition may disappear or improve during the teenage years, although it can return later in life. Moderate or severe childhood asthma is more likely to persist or return later on.
The symptoms of asthma can range from mild to severe. Most people will only experience occasional symptoms, although a few people will have problems most of the time.
The main symptoms of asthma are:
These symptoms are often worse at night and early in the morning, particularly if the condition is not well controlled. They may also develop or become worse in response to a certain trigger, such as exercise or exposure to an allergen.
Read our page on the causes of asthma for more information about potential triggers.
Speak to your GP if you think you or your child may have asthma. You should also talk to your doctor or asthma nurse if you have been diagnosed with asthma and you are finding it difficult to control the symptoms.
When asthma symptoms get significantly worse, it is known as an asthma attack or ‘acute asthma exacerbation’.
Asthma attacks often develop slowly, sometimes taking a couple of days or more to become serious, although some people with asthma are prone to sudden, unexpected severe attacks. It is important to recognise attacks early and take appropriate action.
During an asthma attack, the symptoms described above may get worse and – if you’re already on treatment – your inhaler medication may not work as well as it normally does.
You might be monitoring your asthma using a device called a peak flow meter, and there may be a drop in your peak expiratory flow. Read about diagnosing asthma for more information.
Signs of a particularly severe asthma attack can include:
Phone 999 to seek immediate help if you or someone else has symptoms of a severe asthma attack.
It’s not clear exactly what causes asthma, although it is likely to be a combination of factors.
Some of these may be genetic. However, a number of environmental factors are thought to play a role in the development of asthma. These include air pollution, chlorine in swimming pools and modern hygiene standards (known as the ‘hygiene hypothesis’).
There is currently not enough evidence to be certain whether any of these can cause asthma, although a variety of environmental irritants, such as dust, cold air and smoke, may make it worse.
Although the cause of asthma is unknown, a number of things that can increase your chances of developing the condition have been identified. These include:
Some people may also be at risk of developing asthma through their job.
In people with asthma, the small tubes (bronchi) that carry air in and out of the lungs become inflamed and more sensitive than normal.
This means that when you come into contact with something that irritates your lungs (a trigger), your airways become narrow, the muscles around them tighten, and there is an increase in the production of sticky mucus (phlegm).
Asthma symptoms can have a range of triggers, such as:
Once you know your asthma triggers, you may be able to help control your condition by trying to avoid them.
In some cases, asthma is associated with substances you may be exposed to at work. This is known as “occupational asthma”.
Some of the most commonly reported causes of occupational asthma include exposure to:
You may be at an increased risk of developing occupational asthma if you are regularly exposed to substances such as these through your work.
Occupations that are commonly associated with the condition include paint sprayers, bakers and pastry makers, nurses, chemical workers, animal handlers, welders, food processing workers and timber workers.
If you have typical asthma symptoms, your GP will often be able to make a diagnosis.
They will want to know when the symptoms happen and how often, and if you have noticed anything that might trigger them.
Your GP may also ask whether you have any allergic (atopic) conditions such as eczema and hay fever, which often occur alongside asthma.
A number of tests can be carried out to confirm the diagnosis. These are described below.
In children, asthma can be difficult to diagnose because many other conditions can cause similar symptoms in infants. The tests outlined below are also not always suitable for children.
Your GP therefore may sometimes suggest that your child uses an asthma inhaler as a trial treatment. If this helps improve your child’s symptoms, it is likely they have asthma.
A breathing test called spirometry will often be carried out to assess how well your lungs work. This involves taking a deep breath and exhaling as fast as you can through a mouthpiece attached to a machine called a spirometer.
The spirometer takes two measurements – the volume of air you can breathe out in the first second of exhalation (the forced expiratory volume in one second, or FEV1) and the total amount of air you breathe out (the forced vital capacity or FVC).
You may be asked to breathe into the spirometer a few times to get an accurate reading.
The readings are then compared with average measurements for people your age, sex and height, which can show if your airways are obstructed.
Sometimes an initial set of measurements is taken, and you are then given a medicine to open up your airways (a reliever inhaler) to see if this improves your breathing when another reading is taken.
This is known as reversibility testing, and it can be useful in distinguishing asthma from other lung conditions, such as chronic obstructive pulmonary disease (COPD).
A small hand-held device known as a peak flow meter can be used to measure how fast you can blow air out of your lungs in one breath. This is your peak expiratory flow (PEF) and the test is usually called a peak flow test.
This test requires a bit of practise to get it right, so your GP or nurse will show you how to do it and may suggest you take the best of two or three readings.
You may be given a peak flow meter to take home and a diary to record measurements of your peak flow over a period of weeks. This is because asthma is variable and your lung function may change throughout the day.
Your diary may also have a space to record your symptoms. This helps to diagnose asthma and, once diagnosed, will help you recognise when your asthma is getting worse and aid decisions about what action to take.
To help diagnose asthma that may be related to your work (occupational asthma), your GP may ask you to take measurements of your peak expiratory flow both at work and when you are away from work. Your GP may then refer you to a specialist to confirm the diagnosis.
Some people may also need a number of more specialised tests. The tests may confirm the diagnosis of asthma or help diagnose a different condition. This will help you and your doctor to plan your treatment.
This test is sometimes used to diagnose asthma when the diagnosis is not clear from the more simple tests discussed above. It measures how your airways react when they come into contact with a trigger.
You will be asked to breathe in a medication that deliberately irritates or constricts your airways slightly if you have asthma, causing a small decrease in your FEV1 measured using spirometry and possibly triggering mild asthma symptoms. If you do not have asthma, your airways will not respond to this stimulus.
The test often involves inhaling progressively increasing amounts of the medication at intervals, with spirometry measurement of FEV1 in between to see if it falls below a certain threshold. In some cases, however, exercise may be used as a trigger.
It may also be useful in some cases to carry out tests to check for inflammation in your airways. This can be done in two main ways:
Skin testing or a blood test can be used to confirm whether your asthma is associated with specific allergies, such as dust mites, pollen or foods.
Tests can also be carried out to see if you are allergic or sensitive to certain substances known to cause occupational asthma.
Read more about diagnosing allergies
Reliever inhalers – usually blue – are taken to relieve asthma symptoms quickly.
The inhaler usually contains a medicine called a short-acting beta2-agonist, which works by relaxing the muscles surrounding the narrowed airways. This allows the airways to open wider, making it easier to breathe again.
Reliever inhalers do not reduce the inflammation in the airways, so they do not make asthma better in the long term – they are intended only for the relief of symptoms.
Examples of reliever medicines include salbutamol and terbutaline. They are generally safe medicines with few side effects, unless overused.
However, they should rarely, if ever, be necessary if asthma is well controlled, and anyone needing to use them three or more times a week should have their treatment reviewed.
Everyone with asthma should be given a reliever inhaler, also known simply as a ‘reliever’.
Read further information:
Preventer inhalers – usually brown, red or orange – work over time to reduce the amount of inflammation and sensitivity of the airways, and reduce the chances of asthma attacks occurring.
They must be used regularly (typically twice or occasionally once daily) and indefinitely to keep asthma under control.
You will need to use the preventer inhaler daily for some time before you gain the full benefit. You may still occasionally need the blue reliever inhaler to relieve your symptoms, but your treatment should be reviewed if you continue to need them often.
The preventer inhaler usually contains a medicine called an inhaled corticosteroid. Examples of preventer medicines include beclometasone, budesonide, fluticasone, ciclesonide and mometasone.
Preventer treatment should be taken regularly if you have anything more than occasional symptoms from your asthma, and certainly if you feel the need to use a reliever inhaler more than twice a week.
Some inhaled corticosteroids can occasionally cause a mild fungal infection (oral thrush) in the mouth and throat, so make sure you rinse your mouth thoroughly after inhaling a dose. The use of a spacer device also reduces this risk.
Smoking can reduce the effects of preventer inhalers.
Read further information:
If your asthma does not respond to initial treatment, the dose of preventer inhaler you take may be increased in agreement with your healthcare team.
If this does not control your asthma symptoms, you may be given an inhaler containing a medicine called a long-acting reliever (long-acting bronchodilator/long-acting beta2-agonist, or LABA) to take as well.
These work in the same way as short-acting relievers. Although they take slightly longer to work, their effects can last for up to 12 hours. This means that taking them regularly twice a day provides 24-hour cover.
Regular use of long-acting relievers can also help reduce the dosage of preventer medication needed to control asthma. Examples of long-acting relievers include formoterol and salmeterol, and recently vilanterol, which may last up to 24 hours.
However, like short-acting relievers, long-acting relievers do not reduce the inflammation in the airways. If they are taken without a preventer, this may allow the condition to get worse while masking the symptoms, increasing the chance of a sudden and potentially life-threatening severe asthma attack.
You should therefore always use a long-acting reliever inhaler in combination with a preventer inhaler, and never by itself.
In view of this, most long-acting relievers are prescribed in a ‘combination’ inhaler, which contains both an inhaled steroid (as a preventer) and a long-acting bronchodilator in the one device.
Examples of combination inhalers include Seretide, Symbicort, Fostair, Flutiform and Relvar. These are usually (but not always) purple, red and white, or maroon.
If regular efficient administration of treatment with a preventer and a long-acting reliever still fails to control asthma symptoms, additional medicines may be tried. Two possible alternatives include:
If your asthma is still not under control, you may be prescribed regular steroid tablets. This treatment is usually monitored by a respiratory specialist (an asthma specialist).
Oral steroids are powerful anti-inflammatory preventers, which are generally used in two ways:
Long-term use of oral steroids has serious possible side effects, so they are only used once other treatment options have been tried, and after discussing the risks and benefits with your healthcare team.
Omalizumab, also known as Xolair, is the first of a new category of medication that binds to one of the proteins involved in the immune response and reduces its level in the blood. This lowers the chance of an immune reaction happening and causing an asthma attack.
It is licensed for use in adults and children over six years of age with asthma.
The National Institute for Heath and Care Excellence (NICE) recommends that omalizumab can be used in people with allergy-related asthma who need continuous or frequent treatment with oral corticosteroids.
Omalizumab is given as an injection every two to four weeks. It should only be prescribed in a specialist centre. If omalizumab does not control asthma symptoms within 16 weeks, the treatment should be stopped.
Read further information:
Bronchial thermoplasty is a relatively new procedure that can be used in some cases of severe asthma. It works by destroying some of the muscles surrounding the airways in the lungs, which can reduce their ability to narrow the airways.
The procedure is carried out either with sedation or under general anaesthetic. A bronchoscope (a long, flexible tube) containing a probe is inserted into the lungs through the mouth or nose so it touches the airways.
The probe then uses controlled heat to damage the muscles around the airways. Three treatment sessions are usually needed, with at least three weeks between each session.
There is some evidence to show this procedure may reduce asthma attacks and improve the quality of life of someone with severe asthma.
However, the long-term risks and benefits are not yet fully understood. There is a small risk it will trigger an asthma attack, which sometimes requires hospital admission.
You should discuss this procedure fully with your clinician if the treatment is offered.
Read further information:
Relievers are a safe and effective medicine, and have few side effects as long as they are not used too much. The main side effects include a mild shaking of the hands (tremors), headaches and muscle cramps. These usually only happen with high doses of reliever inhaler and usually only last for a few minutes.
Preventers are very safe at usual doses, although they can cause a range of side effects at high doses, especially with long-term use.
The main side effect of preventer inhalers is a fungal infection of the mouth or throat (oral candidiasis). You may also develop a hoarse voice and sore throat.
Using a spacer can help prevent these side effects, as can rinsing your mouth or cleaning your teeth after using your preventer inhaler.
Your doctor or nurse will discuss with you the need to balance control of your asthma with the risk of side effects, and how to keep side effects to a minimum.
Long-acting relievers may cause similar side effects to short-acting relievers. You should be monitored at the beginning of your treatment and reviewed regularly. If you find there is no benefit to using the long-acting reliever, it should be stopped.
Theophylline tablets have been known to cause side effects in some people, including nausea, vomiting, tremors and noticeable heartbeats (palpitations). These can usually be avoided by adjusting the dose according to periodic measurement of the theophylline concentration in the blood.
Side effects of leukotriene receptor agonists can include tummy (abdominal) pain and headaches.
Oral steroids carry a risk if they are taken for more than three months or if they are taken frequently (more than three or four courses of steroids a year). Side effects can include:
With the exception of increased appetite, which is very commonly experienced by people taking oral steroids, most of these unwanted effects are uncommon.
However, it is a good idea to keep an eye out for them regularly, especially side effects that are not immediately obvious, such as high blood pressure, thinning of the bones, diabetes and glaucoma.
You will need regular appointments to check for these.
Read further information:
A personal asthma action plan will help you recognise the initial symptoms of an asthma attack, know how to respond, and when to seek medical attention.
In most cases, the following actions will be recommended:
If your symptoms improve and you do not need to phone 999, you still need to see a doctor or asthma nurse within 24 hours.
If you are admitted to hospital, you will be given a combination of oxygen, reliever and preventer medicines to bring your asthma under control.
Your personal asthma action plan will need to be reviewed after an asthma attack, so reasons for the attack can be identified and avoided in future.
Read further information:
As part of your initial assessment, you should be encouraged to draw up a personal asthma action plan with your GP or asthma nurse.
If you’ve been admitted to hospital because of an asthma attack, you should be offered an action plan (or the opportunity to review an existing action plan) before you go home.
The action plan should include information about your asthma medicines, and will help you recognise when your symptoms are getting worse and what steps to take. You should also be given information about what to do if you have an asthma attack.
Your personal asthma action plan should be reviewed with your GP or asthma nurse at least once a year, or more frequently if your symptoms are severe.
As part of your asthma plan, you may be given a peak flow meter. This will give you another way of monitoring your asthma, rather than relying only on symptoms, so you can recognise deterioration earlier and take appropriate steps.
Read further information:
Your doctor or nurse will tailor your asthma treatment to your symptoms. Sometimes you may need to be on higher levels of medication than at others.
You should be offered:
It is also important that your GP or pharmacist teaches you how to properly use your inhaler, as this is an important part of good asthma care.
If it is possible you have asthma associated with your job (occupational asthma), you will be referred to a respiratory specialist to confirm the diagnosis.
If your employer has an occupational health service, they should also be informed, along with your health and safety officer.
Your employer has a responsibility to protect you from the causes of occupational asthma. It may sometimes be possible to substitute or remove the substance triggering your occupational asthma from your workplace, to redeploy you to another role within the company, or to wear protective breathing equipment.
However, you may need to consider changing your job or relocating away from your work environment, ideally within 12 months of your symptoms developing.
Some people with occupational asthma may be entitled to Industrial Injuries Disablement Benefit.
Read further information:
A number of complementary therapies have been suggested for the treatment of asthma, including:
However, there is little evidence that any of these treatments, other than breathing exercises, are effective.
There is some evidence that breathing exercises can improve symptoms and reduce the need for reliever medicines in some people. These include breathing exercises taught by a physiotherapist, yoga and the Buteyko method (a technique involving slowed, controlled breathing).
Read further information:
With the right treatment and management, asthma shouldn’t restrict your daily life (including your sleep) in any way. You should work with your healthcare professionals and strive to achieve this goal.
You should also be confident about how to recognise when your asthma is getting out of control, and what to do if it does.
Asthma symptoms are often worse at night. This means you might wake up some nights coughing or with a tight chest.
If your child has asthma, poor sleep can affect their behaviour and concentration, as well as their ability to learn.
Effectively controlling asthma with the treatment your doctor or nurse recommends will reduce the symptoms, so you or your child should sleep better.
Read about living with insomnia for more tips on getting better sleep.
Very occasionally, people with asthma develop symptoms only during exercise. However, usually this is a sign that your asthma could be better controlled generally.
If you or your child have asthma symptoms during or after exercise, speak to your doctor or asthma nurse. It is likely they will review your general symptoms and personal asthma plan to make sure the condition is under control.
Your doctor or asthma nurse may also advise that:
Read about health and fitness for more information on simple ways to exercise.
Most people with asthma can eat a normal, healthy diet. Occasionally, people with asthma may have food-based allergic triggers and will need to avoid foods such as cows’ milk, eggs, fish, shellfish, yeast products, nuts, and some food colourings and preservatives. However, this is uncommon.
Read more about eating well
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It’s important to identify possible asthma triggers by making a note of any worsening symptoms or by using your peak flow meter during exposure to certain situations.
Read our page on the causes of asthma for more information about potential triggers.
Some triggers, such as air pollution, illnesses and certain weather conditions, can be hard to avoid. However, it may be possible to avoid other triggers, such as dust mites, fungal spores, pet fur and certain medications that trigger your symptoms.
Make sure your healthcare team knows about and investigates triggers for your symptoms that you may have noticed yourself.
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Badly controlled asthma can have an adverse effect on your quality of life. The condition can result in:
Children may also feel excluded from their school friends if they cannot take part in games, sports and social activities.
In rare cases, asthma can lead to a number of serious respiratory complications, including:
All these complications are life threatening and will need medical treatment.
Although most people are able to effectively control their symptoms, asthma can be a life-threatening condition.
Often, people who die from asthma do so at home because they do not recognise when their condition is getting worse or leave it too long to take action.
Do not let this happen to you. Be confident in recognising deterioration of your asthma and what action to take. Take action promptly – never ignore severe asthma.
As a result of changes that take place in the body during pregnancy, many women find their asthma symptoms change when they are pregnant. Some women find their asthma improves during pregnancy, while others see it worsen. For others, it stays the same.
The most severe asthma symptoms experienced by pregnant women tend to occur between the 24th and 36th week of pregnancy. Symptoms then decrease significantly during the last month of pregnancy.
Only 10% of women experience asthma symptoms during labour and delivery, and these symptoms can normally be controlled through the use of reliever medicine.
It’s important to ensure your condition is well controlled during pregnancy, because poorly controlled asthma can lead to complications such as pre-eclampsia, premature birth and restricted growth of the baby in the womb. Good asthma control also minimises the chance of problems during labour and delivery.
You should manage your asthma in the same way you did before you were pregnant. The medicines used for asthma – particularly those that are inhaled – are generally considered to be safe to take during pregnancy and when breastfeeding your child.
The one exception is leukotriene receptor antagonists. These are not known to be harmful, but there is insufficient experience of their use in pregnancy to be absolutely certain.
If, however, you do need to take leukotriene receptor antagonists to control your asthma, you may decide (in discussion with your GP or asthma clinic and obstetrician) that you should carry on taking them and that the potential risks to you and your child from uncontrolled asthma are likely to be far higher than any potential risk from this medicine.
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Most children with well-controlled asthma can learn and participate in school activities completely unaffected by their condition.
However, it is important to ensure the school has up-to-date written information about your child’s asthma medicines, how much they take, and when they need to take them.
You may also need to supply the school with a spare reliever inhaler for your child to use if they experience symptoms during the school day.
Staff at the school should be able to recognise worsening asthma symptoms and know what to do in the event of an attack, particularly staff supervising sport or physical education.
Your child’s school should have an asthma policy in place, which you can ask to see.
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Depending on how severely asthma affects you on a daily basis, you may be entitled to some benefits, such as:
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If you develop asthma because of your work, and this is fully documented by your doctor and your employer, you can make a claim for Industrial Injuries Disablement Benefit from the Benefits Agency.
This is a weekly amount paid to people with asthma caused by exposure to a specific substance through their work and is known to be associated with asthma (a complete list is available from the Health and Safety Executive).
If you want to take legal action against your employer because of occupational asthma, your lawyer must act within three years of diagnosis.
Read further information:
Many people with a long-term health condition experience feelings of stress, anxiety and depression.
You may find it helpful to talk about your experience of asthma with others in a similar position. Patient organisations have local groups where you can meet others who have been diagnosed with asthma and have undergone treatment.
If you experience feelings of depression, talk to your GP. They will be able to give advice and support. Alternatively, find depression support services in your area.
Last updated:
13 February 2023