Asthma (Adults)

Respiratory system

Asthma is a common condition that affects the small airways or tubes in the lungs called bronchioles, making it difficult to breathe.

Asthma is a very common condition, estimated to affect one person out of every 5 households in the UK. Currently, there are over 5.4 million people receiving treatment for asthma in the UK, of which over 1.1 million are children. Worryingly, the number of children affected by asthma is on the increase. There are over 1200 deaths per year in the UK caused by asthma.

No one knows exactly why some people develop asthma and others do not. It is probably a combination of genetic and environmental factors. People are more likely to develop asthma if there is a history of asthma, allergy or eczema in the family. Environmental factors such as house dust mite, pollution, smoking (including passive smoking and smoking during pregnancy), or a viral infection probably combine with genetic factors to increase the chances of getting asthma.

When a person develops asthma, the cells in the airways become overly sensitive and are easily irritated. When this happens, it becomes difficult for the person to breathe and the person is said to be suffering from an asthma attack.

To understand what is happening during an asthma attack, it is important to know something about the structure of the airways.

The small airways in the lungs, called the bronchioles, have an outer muscular wall and a soft inner lining. The outer muscular wall controls the size of the opening of the airway. When the muscles relax the opening of the airways gets bigger, making it easier to breathe and allowing more air into the lungs. This process is referred to as bronchodilatation. When the muscles contract the opening of the airways gets smaller, making it harder to breathe and allowing less air into the lungs. This process is referred to as bronchoconstriction or bronchospasm. The cells of the soft inner lining of the bronchioles produce mucus that traps dust and other small particles in the air that is breathed, helping to clear these unwanted substances from the lungs.

During an asthma attack, the muscles in the walls of the airway contract (bronchospasm) making it difficult to breathe. At the same time, the inner lining of the airway becomes swollen or inflamed and produces lots of mucus. The swelling of the lining and the increased amount of mucus make the narrowed airway even narrower and breathing even more difficult.

Many things may trigger an asthma attack. These include things that are breathed into the lungs, such as dust, pollen, cigarette smoke and animal fur. Cold air or exercise may trigger an attack, as can stress or a chest infection. Some medicines are also capable of triggering an asthma attack if the person is sensitive to them. Everybody is different, not everyone will respond to the same triggers and some people may have several triggers.

Symptoms of asthma may vary from the very mild to the life threatening. In their mildest form, the person affected may have a slight cough or a wheeze. More severe symptoms include tightness in the chest and shortness of breath. Symptoms vary from day to day and are often worse during the night or during exercise. In its severest form, an asthma attack may come on very suddenly and the person will not be able to breathe.

The treatment of asthma falls into two main categories - relievers and preventers. Relievers work quickly to ease the symptoms of an asthma attack. They should be used at the first signs of an asthma attack beginning. Preventers help reduce the number of asthma attacks by reducing the sensitivity of the airways to triggers. Preventers need to be taken all of the time, even when the person is breathing normally. Most relievers and preventers are available as inhaler devices that deliver the active medicine directly into the lungs. Some are also available in liquid or tablet form to be taken by swallowing.

Relievers
Relievers include drugs known as short-acting beta2 agonists, for example salbutamol and terbutaline. These drugs act on the muscles in the airways making them relax, producing bronchodilatation and so making breathing easier. For this reason, these drugs are also called bronchodilators. Both salbutamol and terbutaline act quickly, so when taken at the first sign of an asthma attack can help relieve symptoms. The actions of both drugs may only last for a few hours which means that doses may need to be repeated to control the asthma attack.

Other relievers include drugs known as anticholinergics, for example ipratropium bromide. This drug also causes bronchodilatation but it is not as fast acting as salbutamol and is not used for the relief of asthma attacks. Instead, it is usually used with other treatments when asthma symptoms fail to improve.

Preventers
Preventers include drugs known as inhaled steroids, for example beclometasone, budesonide, ciclesonide, fluticasone and mometasone. These drugs act to reduce the sensitivity of the airways to triggers. When taken regularly they reduce inflammation of the airways and reduce mucus secretion. They need to be taken regularly to be effective.

Long-acting beta2 agonists, for example formoterol and salmeterol also cause bronchodilatation but because they act slowly they are not suitable to relieve acute asthma attacks. They are normally used with inhaled steroids to help the long term control of asthma symptoms. They should not be used to replace steroids as this may cause life threatening asthma attacks. The long-acting beta2 agonists may also be useful in controlling asthma attacks that occur during the night.

Montelukast and zafirlukast, drugs known as leukotriene antagonists, may also be added to standard bronchodilator and steroid therapy to control asthma. These drugs come in tablet from rather than as inhalers, and inhibit the action of a chemical called leukotriene that is released in the lungs during an asthma attack and which is responsible for causing inflammation.

As the various asthma treatments have different actions or are used for different purposes, several products are often used together to help control asthma. Most asthma patients will require regular treatment everyday to reduce their symptoms, and also treatment for relief if an asthma attack suddenly occurs. Treatment will depend on the severity of the asthma, and it may change from time to time as symptoms ease or get worse.

Asthma is a long term condition that may require treatment for years. In such circumstances it is worth registering with your pharmacist for the repeat dispensing of your prescriptions. By doing so, your pharmacist will get to know you and the medicines that you are taking and is always available to offer advice. At regular intervals, your pharmacist may suggest that he or she reviews the medicines that you are taking to ensure that you are using them properly and that they remain right for you. It also provides an opportunity for you to discuss any questions about your medicine and how it should be used. If your pharmacist considers that your asthma is not being controlled, you will be advised to visit your doctor or asthma specialist nurse.

Your doctor or asthma specialist nurse is in the best position to advise you. With good advice and modern medicines, it is possible for most people to control their condition and lead a life unrestricted by their asthma. Most of the treatments available now are easy to take, and in the recommended doses, are effective and carry little risk of causing side effects.

Asthma can not be cured, but with the avoidance of triggers, proper monitoring and the correct treatment it can be controlled, allowing you to do the things that you want to do.

Identifying and, if possible, avoiding the things that trigger an asthma attack will help reduce the number of attacks. For example, if cigarette smoke or animal fur triggers an attack, avoiding smoky places or contact with the animal will reduce the chance of an asthma attack. If you are sensitive to aspirin, get into the habit of reading the labels on medicines and remember that aspirin and aspirin-type products may be described in different ways. If in doubt, talk to your pharmacist before buying any over the counter medicines to relieve pain, or cold and flu symptoms.

Unless specific foods are known to make your asthma symptoms worse, there is no need to have a special diet. Just eat a healthy, balanced diet rich in fresh fruit and vegetables and keep your weight under control.

Exercise regularly, aim for 30 minutes of active exercise five times per week, doing an exercise that you enjoy doing. Take it easy at first and build up your activity levels gradually. Use your reliever before starting to exercise if you know that exercise triggers your asthma, and keep your reliever with you. If symptoms start, stop exercising, use your reliever and rest until your symptoms go.

Get to know your symptoms. It will help you recognise how well your asthma is being controlled. A simple device called a peak flow meter can be used to help measure how well the lungs are working. When used regularly and the results recorded in a diary, a peak flow meter can help give an advance warning of worsening symptoms of asthma.

Use your medicines as your doctor or asthma specialist nurse advises and you will be playing your part in successfully managing your asthma. Tell your doctor or nurse about any changes in your symptoms or your use of medicines. For example, if you are using your reliever inhaler more than once a day, if you are coughing or wheezing regularly, waking up at night or just not able to do things that you could before your asthma, then it may just mean that your asthma is not as well controlled as it might be.

The goals of asthma management are listed below. Ask yourself if you are achieving them, if not see your doctor or nurse.

Goals of asthma treatment:

• Be free from symptoms day and night
• Restore normal or best possible lung function, and maintain it
• Reduce the risk of severe attacks
• Minimise absence from school or work

Asthma UK is the charity dedicated to improving the health and well-being of people in the UK whose lives are affected by asthma. Asthma UK runs an advice line operated by asthma specialist nurses. Its website provides comprehensive information about asthma and gives practical advice on its management.
Asthma UK Adviceline
Asthma UK
Summit House
70 Wilson Street
London
EC2A 2DB
Helpline: 0800 121 62 44
www.asthma.org.uk
To find out more about Asthma UK around the UK, contact:

Asthma UK
Summit House
70 Wilson Street
London
EC2A 2DB
Tel: 020 7786 4900
Fax: 020 7256 6075
Email: info@asthma.org.uk
Asthma UK Scotland
4 Queen Street
Edinburgh
EH2 1JE
Tel: 0131 226 2544
Fax: 0131 226 2401
Email: scotland@asthma.org.uk

Asthma UK Cymru
3rd floor
Eastgate House
34-43 Newport Road
Cardiff
CF24 0AB
Tel: 02920 435 400
Fax: 02920 487 731
Email: wales@asthma.org.uk
Asthma UK Northern Ireland
Ground floor
Unit 2
College house
City Link Business Park
Durham Street,
Belfast
BT12 4HQ
Tel: 0800 151 3035
Email: ni@asthma.org.uk

Reviewed on 6 December 2010