Asthma.
Tom works for the Post Office, sorting mail on a night shift. ‘After work, I come out of the sorting office - it’s about five or six in the morning, and really cold - and when I suddenly hit the cold air, I feel as if I just can’t breathe. My chest clamps up like anything, so much that it hurts. Then, when I get in the car and put the heater on, it’s fine again.’
What Tom is describing is bronchospasm, the key event in asthma – a sudden, but reversible, tightening of the bands of muscle that surround the airways. The narrowed airways stop air from leaving the lungs at the normal speed, which means the lungs are still half-full when it’s time for the next in-breath.
Taking more air into half-full lungs produces pain and tightness in the chest, as the lungs become over-inflated. (This can be alarming, because it can seem like pain from the heart, but it is just the rib joints and chest muscles hurting as they become stretched.)
Insufficient oxygen reaches the bloodstream because there is so much stale air in the lungs, so the asthmatic also feels breathless. Meanwhile, the air being forced through the narrowed airways makes a whistling sound called wheezing.
Those are the common symptoms of asthma, but there are others:
• Coughing, rather than wheezing, is the main symptom for some people (see box on p. 40).
• Sometimes there is vomiting during an asthma attack, especially in children, because the
overexpanded lungs put a great deal of pressure on the stomach.
• A few asthmatics suffer narrowing in the trachea (the upper part of the windpipe) rather than
in the airways lower down, and therefore feel as if they are being strangled.
Bronchospasm is just the endpoint of the disease process in asthma, a process which begins with inflammation of the lining of the airways. Although the airway muscles relax when an asthma attack is over, and you therefore feel much better, the underlying inflammation of the airways remains.
Airway inflammation may be caused, or partially caused, by allergy. Among asthmatic children, allergies are detected in 80-90%.
Inflammation makes the lining of the airways swell up, which itself narrows the airways a little. The inflamed airway lining often makes more mucus than usual, in an effort to protect itself (this is basically a healthy response – mucus works like a sponge mopping up irritating dust particles so that they can be ejected by coughing – but it’s excessive in asthma). This mucus can clog up the airways even more. Finally, the inflamed airways send nerve impulses direct to the airway muscles telling them to contract.
Mucus alert
Asthmatic mucus is white or clear, and sometimes frothy. Greenish or yellowish mucus suggests an infection and should be reported to your doctor.
In severe cases of asthma, a lump of mucus can completely block an airway, leading part of the lung to collapse. It is vital to clear mucus from the lungs, and a physiotherapist can help with this.
What causes asthma?
This question can be answered at three different levels:
1 What makes someone predisposed to asthma?
2 What starts asthma off – in other words, what starts the inflammation process in the airways?
3 What triggers asthma attacks (episodes of bronchospasm)?
What makes someone predisposed to asthma?
The predisposition to asthma is partly inherited (see p.
and partly a matter of lifestyle: a poor
diet makes asthma more likely (see p. 206), as does too much cleanliness (see p. 21), obesity and lack of exercise.
What starts off the inflammation?
The predisposition to asthma sets the stage, but it does not, in itself, start the inflammation of the airways. That is often begun by an allergic reaction to something in the air – such as house-dust mite or pet allergens.
Alternatively, the initiating factor could be a viral infection, especially a kind known as Respiratory
Syncytial Virus or RSV – there are epidemics of RSV every two or three years. Those predisposed to
asthma may make an abnormal kind of immune response to chest infections caused by viruses, a response
that shifts the balance of the immune system towards Th2 cells (see p. 11) and allergy-type reactions.
Although the infection is defeated by the immune system, some inflammation of the airway lining
remains.
A heavy dose of certain irritants, such as chlorine, or the substances used in spray-painting cars, can
also initiate asthma; this mainly occurs in a workplace setting, causing occupational asthma (see box
on p. 133).
What triggers asthma attacks?
Once the inflammation of the airways has begun, the airways are ‘twitchy’ –oversensitive – and the
airway muscles contract (i.e. bronchospasm occurs) at the smallest provocation. This contraction of the
muscles – an asthma attack –can be caused by irritants in the air, such as tobacco smoke, or a great
variety of other things. The possible triggers range from cold air or the scent of hyacinths, to
thunderstorms, laughter or anxiety – see p. 39 for a full list. Exposure to the allergens that started
the inflammation will also trigger an asthma attack, as will a virus (viral) infection such as a cold
or flu.
For many asthmatics, the breathing pattern is disturbed by the asthma attacks, and may remain abnormal
between attacks. Hyperventilation or ‘over-breathing’ can begin quite easily for asthmatics, and then
adds to the overall problems. It may be difficult to tell if you hyperventilate or not, because your
habitual pattern of breathing will seem normal to you, but there may be tell-tale symptoms such as
dizziness, tingling of the hands and feet, numbness and muscle cramps. For a full list of symptoms see
p. 227.
Mind power
The muscle of the airways is the kind of muscle over which we have no conscious control, like that of
the heart. It is known as involuntary muscle, whereas muscles in the arms and legs, which contract or
relax when we tell them to, are called voluntary muscles. Studies with biofeedback have shown that
asthmatics may, with training, gain some degree of control over these involuntary muscles. Experienced
yoga practitioners are able to influence certain involuntary muscles, including those in the airways.
There are also various ways in which the mind, or a person’s social and emotional situation, can make
asthma worse (see p. 234) but the damaging idea that it is an entirely ‘psychological’ disease is now
discounted.
Allergens and irritants
Understanding the difference between allergens and irritants is important for asthmatics. Allergens are
specific — either pollen is an allergen for you or it isn’t, depending on how your immune system reacts
to it. They are also a basic cause of asthma — they start it off.
Irritants, on the other hand, are non-specific: they affect every asthmatic if sufficiently
concentrated, causing bronchospasm by aggravating the airway lining. And, at the levels usually
encountered, they only cause trouble because the inflammation of the airways has already occurred.
Irritants include cigarette smoke, other smoke and some industrial fumes, ozone (see p. 130), sulphur
dioxide (given off by some foods and drinks — see box on p. 207), fly spray, air freshener and other
aerosols.
Diagnosis
There are four separate aspects to diagnosis:
1 Is this really asthma or something else entirely?
2 Is it combined with other diseases, and how are they affecting the asthma?
3 What is the basic cause of the inflammation in the airways, and can this be avoided?
4 What sort of factors trigger the asthma attacks?
You may not get this full diagnostic programme, but you can probably help in finding answers to some of
the questions.
Is this really asthma or something else entirely?
There are no tests that can diagnose asthma with complete certainty, but the average case of adult
asthma is pretty easy to spot, and the same is true for children over five. It is also true, however,
that some patients now described as asthmatic would have been given a different diagnosis (e.g. wheezy
bronchitis) thirty years ago. To some extent, this is because asthma was under-diagnosed in the past:
doctors were hesitant about giving a diagnosis of asthma, because of the supposed overtones of
psychosomatic disease. Sweeping away that stigma has been of immense value, but certain patients
(especially young children) may now get diagnosed as asthmatic without sufficient evidence. However,
there are also many instances of asthma being missed.
There are two tests that should be carried out before you are given a diagnosis of asthma:
1 Peak flow is the top speed of the outgoing air from your lungs, usually measured with a simple
portable machine called a peak-flow meter. Because of the narrowed airways, asthmatics have a lower
peak flow than normal.
2 The reversibility test depends on measuring peak flow before and after inhaling a beta-2 reliever
drug which relaxes the airway muscles (see p. 152). If the drug improves peak flow by more than 15%,
this strongly suggests asthma.
Asthma may be difficult to diagnose in certain situations:
• In babies, who often wheeze, especially when they have colds or chest infections. This
generally clears up later and does not automatically develop into asthma. There is great controversy
about whether wheezy babies should be labelled ‘asthmatic’ or not, and how bad the wheezing should be
before they are given asthma drugs. Views on this vary, so you may want to see a different doctor for a
second opinion. For older children who wheeze only when they get chest infections, most doctors feel it
is valuable to use asthma drugs – such treatment does not ‘turn wheezing into asthma’
as is sometimes claimed. (There are several things you can do to minimise the chance of early wheezing
turning into asthma later – see pp. 244-9.)
• When the main symptom is coughing (see box on p. 40).
• When asthma occurs only at night. In some asthmatics, even intensive testing reveals no
abnormality in the airways during the day. The only way to diagnose the condition is to use a peak-flow
meter at home, morning and evening.
• When there is a sudden one-off asthma attack in response to a powerful allergen load. This
sometimes happens to hayfever sufferers at the height of the pollen season (especially during
thunderstorms). Some doctors will want to start asthma drugs immediately, but it may be better to get
the hayfever well controlled with antihistamines and see what happens. Often there are no further
asthma attacks.
Then there are conditions that can be mistaken for asthma:
• In children, an inhaled object – such as a nut or part of a toy – becoming stuck in the
airways. In babies it can also be inhalation of milk droplets; if so, the ‘asthma’ comes on mainly
after feeding.
• Post-nasal drip (see p. 29)
• Heiner’s Syndrome – (see p. 72)
• Bronchiolitis: a viral infection (generally caused by RSV –see p. 37) which affects the small
airways (the bronchioles) of babies and toddlers. Unlike asthma, it usually produces fever.
• Gastro-oesophageal reflux (GER), or the rising of acid from the stomach into the oesophagus.
(This is commonly called heartburn, after its most typical symptom, but you can suffer from GER without
having heartburn.) GER can aggravate existing asthma, and it can also be an asthma mimic. Babies,
children and adults can all suffer from this problem. There will usually be clues such as symptoms that
come on at night after a late supper, or whenever lying down.
• Hyperventilation (see p. 227) in non-asthmatics can be misdiagnosed as asthma if it causes
breathlessness.
• Aspergillosis (see box on p. 18)
• Problems with the vocal cords. Habitually contracting the vocal cords on the in-breath makes a
loud wheezing sound and can cause breathlessness. This problem can mimic asthma, but it also affects
those who really are asthmatic. The cause may be psychological.
• Low-level carbon monoxide poisoning, generally from gas fires, which can cause breathlessness
and fatigue.
• Bronchlectasis: stretching and damage to the airways caused by diseases caught in childhood,
such as pneumonia or whooping cough. This causes lifelong breathlessness.
Is it combined with other diseases, and how are they affecting the asthma?
Any allergic problems in the nose will contribute to asthmatic symptoms in the lungs, because there are
nerve-connections between the two. Long-term sinusitis can also make matters worse. Optimum treatment
for the nasal and sinus symptoms (see pp. 28-35) will help considerably with the asthma.
One unlikely source of asthmatic symptoms has only recently been recognised: allergies can develop to
the fungi causing athlete’s foot, or other diseases (see pp. 16-17).
GER (see p. 38) can contribute substantially to asthma. In some people, the reflux causes no obvious
symptoms, apart from worsening the asthma; medical tests can show that reflux is occurring. Your doctor
can advise on this, and on treatment.
For older people, especially veteran smokers, asthma may be part of a larger picture of inflammation
and damage to the air sacs of the lung (emphysema) and/or to the airways (bronchitis). This mosaic of
problems is known as chronic obstructive pulmonary disease (COPD). It may be difficult to tell if there
is asthma present, or how much it is contributing to the overall problem. Since many patients with COPD
are helped by asthma drugs, and trying out the drugs does no harm, doctors often prescribe them just to
see what happens.
What is the basic cause of airway inflammation? Skin-prick tests are usually needed here, to check for
allergic reactions. It may be difficult to get these in Britain, where there is a shortage of
allergists (see p. 89).
Simple detective work may pinpoint allergens without the need for tests. The likely suspects are all
airborne allergens – see p. 28. Remember that the reaction does not generally start as soon as exposure
to the allergen begins: there is a time-lag. So a new dog or cat, or an allergen encountered at work,
may cause no trouble for the first year or two.
Some irritants can also be a basic cause of asthma, but only if encountered in high doses, which
usually occur in the workplace. These are called asthmagens (see box on p. 133).
In all cases, removing the allergen or irritant from the airways should be a top priority. The sooner
you can end the exposure, the more likely you are to shake off the asthma, rather than have it for
ever. Once the inflammation of the airways is firmly established, it just fuels itself – so act
quickly.
In a minority of cases, food sensitivity is the initiating cause of asthma. The reaction to food is
delayed, so the link will not be obvious. Skin-prick tests for the culprit food are usually negative,
so an elimination diet (see p. 194) is needed to diagnose this problem and identify the food concerned.
Those most likely to benefit are brittle asthmatics (those most severely affected) – as many as 60%
have a food sensitivity. There are various other clues that food could be a factor (see p. 69).
When asthma begins in adulthood, there may be no clear initiating cause – it is just a question of
long-term damage and irritation to the airways. But there can be allergens playing a part, so it is
worth investigating this possibility.
What sort of factors trigger the asthma attacks?
Most asthmatics will recognise one or more of these as triggers:
• cold or dry air
• strong smells including perfume and fragrant flowers
• irritants in the air (such as cigarette smoke and other indoor pollutants, traffic fumes,
industrial pollutants); indoor pollution is often the worst, especially if you have a gas cooker
without adequate ventilation, so there is a lot you can do to improve the air you breathe (see pp.
128-30)
• sulphur dioxide given off by preservatives used in some food and drink (see box on p. 207)
• weather conditions, particularly thunderstorms
• laughing, sighing, yawning, coughing or any other altered breathing pattern
• stress or anxiety
• strong emotions such as fear, anger or excitement
• situations or people that evoke unpleasant memories –including traumatic childhood memories;
sometimes psychotherapy is needed to sort out such problems (see p. 233)
• exercise (because breathing hard dries out the airways)
• the allergens responsible for the asthma, e.g. cat allergen
• colds, flu and chest infections.
Recording your symptoms day-by-day should help to identify the triggers that are most powerful for you.
Generally speaking, such triggers should be avoided, but this is not the case for exercise which does
much more good than harm, in the long run – without exercise, your asthma will get far worse (see p.
41).
Take care with aspirin
Aspirin sensitivity can develop unexpectedly in asthmatics, especially those with allergic rhinitis
and/or nasal polyps (see box on p. 28). It can produce a severe, even fatal, asthma attack in someone
who has previously been able to take aspirin (see p. 151).
Treatment
The first and most important aspect of asthma is environmental control – to try to minimise contact
with allergens and irritants. If you are asthmatic and you smoke, you must stop, because this will only
make matters worse by stoking up the inflammation. Any other smokers in the family should accept that
from now on this is an outdoor activity.
One of the aims of good asthma treatment is to calm the airways down, so that they are less sensitive
and ‘twitchy’. This means tackling the inflammation. You can do this with preventer drugs such as
steroids or cromoglycate (see p. 157), or with the new anti - leu kotriene drugs (see p. 159), or you
can simply remove the basic cause of the trouble, if it is a domestic allergen source, such as a cat, a
dog or house-dust mites.
Treating associated diseases such as sinusitis, hayfever, perennial allergic rhinifis, gastroesophageal
reflux (GER – see p. 38) and athlete’s foot (where this is adding to the symptoms – see p. 16) can also
help in reducing the airway inflammation. Eating a better diet may make a further contribution to
calming the airways down (see p. 206).
The second strand of treatment is to deal with bronchospasm (contraction of the airway muscles) when it
occurs. This is done with reliever drugs such as Ventolin and Atrovent (see p. 152). Note that these
only relieve the symptoms of an asthma attack, and do not address the underlying problem of
inflammation. What is more, if used too frequently (more than once a day) they may increase the risk of
a fatal or near-fatal asthma attack (see p. 153).
At one time, reliever drugs were the mainstay of asthma treatment, and were perceived as entirely safe,
while preventer drugs such as steroids were only given to those with severe asthma. All this has
changed, and most asthmatics, other than those with very infrequent attacks, are now given a
pre-venter. If your drug regime has not been reviewed for some time, make an appointment with your
doctor and check that you are getting the best of the modern treatments.
Drug treatment of asthma is not something you can just hand over to the doctor – it requires a lot of
personal decision - making. If you usually get worse when you have a cold, for example, you need to
Just a cough?
For some, coughing is the main symptom of asthma. Known as cough-variant asthma, this is not always
diagnosed correctly, especially in children. For children with recurrent coughing (two or more episodes
per year of coughing without a cold) it may be a long time before the doctor considers asthma. But
other doctors may diagnose a coughing child as `asthmatic’ all too readily, without doing enough tests.
The important point is that asthma involves episodes of bronchospasm – contraction of the airway
muscles. Without this it is not asthma. Bronchospasm can be detected by medical tests such as peak-flow
readings. Wheezing is one possible symptom of bronchospasm, but coughing is another.
If there is only coughing as a symptom, and never any wheezing, this is probably not asthma. Among
children with this pattern of symptoms, allergies are unlikely to be involved. The cause of such
coughing may be:
• in children, the effects of parental smoking
• in those with perennial allergic rhinitis (see pp. 28-9) mucus from the nose running into the
lungs. This is called post-nasal drip and produces a persistent cough.
• in the middle-aged, eosinophilic bronchitis. This is caused by an influx of eosinophils (see p.
19) into the airway lining, causing inflammation. Allergies do not seem to play a part (it is no more
common in atopics than anyone else) and the airway muscles do not contract abnormally. Treatment is
with inhaled steroids.
• in atopics (those prone to allergies), a condition sometimes called atopic cough. It involves
eosinophils congregating in the trachea (windpipe) and bronchi, but not in the lower airways. There is
inflammation but no airway narrowing. Very little is known about this disease at present; it may or may
not involve allergies. Again, inhaled steroids are effective.
• for a few people, habitual coughing. This is usually an expression of some underlying emotional
difficulty and responds to psychological treatments. The cough often has a honking or barking sound.
Any of these can be misdiagnosed as asthma. For patients with eosinophilic bronchitis or atopic cough,
this is no tragedy as they will probably get the right treatment (inhaled steroids) anyway. But if more
exact diagnostic criteria are being used (e.g. a reversibility test – see p. 38) such patients will not
be classed as asthmatic – this is more of a problem because they may not get appropriate treatment.
increase your dose of preventer as soon as a cold appears, to stop airway inflammation before it
starts. You also need to know when an asthma attack is serious enough to warrant calling an ambulance.
A management plan, worked out with your doctor, is a useful aid (see p. 96). Using a peak-flow meter,
night and morning, to monitor your asthma will also be valuable (see p. 97).
The third strand of asthma treatment is to deal with associated problems:
• Panicky reactions during asthma attacks –which make matters infinitely worse – can be dealt
with by meditation, yoga, relaxation techniques or martial arts training (see p. 222).
• Hyperventilation, which plays a much larger role in asthma than previously suspected, can be
tackled by a variety of methods (see p. 228).
• The distortions of the rib-cage that develop in severe asthma can be treated with osteopathy.
• Losing weight, if you are very heavy, will help ease the burden on your breathing.
Exercise and asthma
Exercise-induced asthma is best tackled, paradoxically, by taking exercise. As your fitness improves,
you don’t pant so hard when exercising, so your airways dry out much less. Countless asthmatics will
tell you that once you overcome the first hurdle – of wheezing the minute you start to exercise –
things get a great deal easier. You will need reliever drugs, and possibly extra preventer, to help you
over this hurdle, but it’s worth it. Warming up with a few sharp sprints, separated by a rest period,
will also help. (If you get an asthma attack while exercising, however, you should always stop –
carrying on regardless can be fatal – literally. Always have your reliever inhaler with you when you
exercise and use it if you get an attack.)
Swimming is an excellent starting point for unfit asthmatics, because the moist air prevents the
airways from drying out. Swim outdoors if you can, since chlorine can be an irritant.
Once you are fitter, regular strenuous exercise makes the breathing muscles stronger, which is of great
benefit – this can also be achieved with special exercises (see p. 231).
Don’t underestimate asthma
Asthma can be fatal, so never take it too lightly. If you often wake up in the night with asthma, you
cannot keep up with most other people your age, or are frequently breathless when climbing stairs or
walking uphill, then your asthma is not under control. The same is true if you need your reliever
inhaler more than once a day, or frequently need steroid tablets. Review your treatment with your
doctor because you probably need more preventive treatment such as inhaled steroids (see p. 157) or
anti-leukotriene drugs (see p. 149).
Recognising an asthma attack and knowing when to call for help, or go to the hospital, is also crucial
(see p. 100). Remember that fatal asthma attacks often come on very quickly – half those who die do so
within two hours of the attack starting, and a quarter die within 30 minutes. Those who die are
generally people who have neglected their preventer medication, or have been exposed to very high
levels of allergens.
There is a major organisation involved in asthma prevention, by the name of Asthma UK. They work together with people with asthma, health professionals and researchers, to develop and share expertise to help people increase their understanding of asthma, and asthma prevention, allowing them to voice their concerns to the people who matter and reduce the effect of it on their lives. They are the only charity dedicated to asthma prevention by improving the health and well-being of people with asthma and are funded by voluntary donations, indeed they are responsible for nearly £3m of asthma research each year for the cause of asthma prevention.
A form of asthma prevention can be in the improvements in environmental quality to benefit everyone in the school building because pollutants have a universally negative effect. For example, for the benefit of the students, schools should undertake extensive building repairs, painting, cleaning, and extermination during long vacations. They should replace plastic furniture and carpeting, which often emit pollutants in the form of noxious gases. For further asthma prevention, they should limit use of cleaning supplies and equipment that emit toxic fumes and strong odours which again are pollutants, and require good ventilation when they are used. They should have the entire building (particularly the heating and ventilation system) cleaned regularly to eliminate dust mites, mildew, animal dander, feathers, cockroaches, and other possible asthma and allergy triggers, and make sure that leaks of water and plaster dust are stopped and quickly cleaned up. Additionally the can help in asthma prevention by regularly monitoring the air quality of schools, especially those in sealed buildings and try to increase the ventilation so that pollutants can escape. All this can help with asthma prevention. So whilst schools may not be able to eliminate other pollutants, such as chalk dust, they can, as an act of asthma prevention, find out which of them are triggers for particular students and try to limit the student’s exposure to them. Further, sensitive scheduling can keep students with specific sensitivities away from certain art supplies and animals, which may enhance the education of some students but sicken students with asthma.
As an asthma prevention in Scandinavia, cross-country skiers sometimes wear breathing masks which store the heat and moisture from the air they breathe out and then return it to the air they breathe in. This is helpful in avoiding exercise-induced asthma. Good control of your asthma, whether by breathing in a ‘preventer’ treatment or by avoiding causes of asthma such as house dust mites and pets can have a tremendously helpful effect on exercise-induced asthma. Reliever inhalers can be tremendously helpful in asthma prevention if you use them just before you exercise. This applies especially to the so-called ‘beta-2 stimulants’ such as salbutamol (albuterol) or terbutaline. The benefit should last for hours. Long-acting reliever inhalers are also very helpful; they just work for longer. If you are a competitive athlete or sportsman, you may be concerned about disqualification because you use drugs. The good news is that all the ordinary asthma medicines, used in the medically recommended way and dosage, are acceptable to sporting bodies provided you use them correctly for asthma. The wise thing is to check with your sports authority or sports doctor. Asthma prevention is good asthma management!
There are oral asthma medications that an individual can take to control their asthma, inhaled at the onset of an asthma attack. People with asthma can carry a peak flow meter; a hand-held tool for measuring their air flow to determine whether an attack is imminent, thus requiring their asthma medications. With help from medical providers and age-appropriate printed materials, children can learn to monitor their asthma and self-medicate with their asthma medications. Taking such control of their asthma medications not only decreases its symptoms, but also promotes the children’s feelings of self-confidence, with the management of their asthma and its medications.
There are dozens of asthma medications available in the UK; the most frequently prescribed of these medications being: Ventolin; Bricanyl; Becodite; Pulmicort; Intal and Tilade. The first 2 asthma medications are essentially relievers, whilst the others are preventers. The preventer drugs are taken by an inhaled route and must be taken regularly to gain maximum effect. They belong to either the steroid or anti-inflammatory groups of asthma medications. The reliever drugs do not need to be taken as often; indeed there is evidence to support that these medications are more effective when they are taken only occasionally. Naturally there will be a concern about side effects, but in the main, asthma medications are safe and free from problems.
One such treatment which can have side effects is a steroid called prednisolone; which is taken by tablet form. These asthma medications dampen down and reduces inflammation, swelling and phlegm. There is a soluble form of these medications called Prednesol, which is useful for children and people who struggle to swallow tablets. If used in short courses there should be no risks at all; it is only when these asthma medications are prescribed over a period of years that certain side effects can occur. These include skin changes, thinning of the bones, increased blood pressure, indigestion, ulcers and the development of diabetes. Once again the emphasis is on serious long term prescriptions of these asthma medications and a brief course has no history of causing any of the above side effects.
Asthma is not an allergy as such, but there are asthma triggers, which can be caused by an allergic reaction to any number of incidents. If you have asthma, your air passages are irritable. This means things which are harmless to other people may be asthma triggers to an asthma sufferer. Various asthma triggers include: (i) Emotional stress - people with asthma often say their asthma gets worse if they are upset. (ii) Cold air - if you move from warm indoor air to cold air outdoors it can affect the air passeges. (iii) Pollution, in particular tobacco smoke - e.g. in a pub, can be one of the more common asthma triggers. (iv) Grass pollen - particularly when exposed to a recently mown lawn. (v) House dust mites - often attracted by central heating. (vii) Pet fur - especially during the malting season can affect the air passeges. (viii) Exercise - can provoke narrowing of the air passages. (ix) Infections of the lining of the breathing passages - e.g. colds and ‘flu. (x) Some drugs - especially medicines called beta blockers used for high blood pressure or heart disease have been known to be asthma triggers. (xi) Indigestion - also called gastro-oesophageal reflux, with stomach acid coming up into your gullet. (xii) Laughing - so don’t laugh! (Only joking, but it can happen). All the above reflect the irritability of the air passages in asthma, even if some of them do so in somewhat different ways, they all can be asthma triggers.
There have been significant changes in air quality over the past few decades. Pollution, from the burning of coal, which resulted in emissions of sulphur dioxide and particulate matter has decreased considerably; however, the frequency of peaks of traffic related pollution and the geographical extent of it have probably increased. Episodes of pollution from secondary pollutants, notably ozone, produced by photochemical oxidation, have also increased and this is one of the chief asthma triggers. Moreover, there have also been changes in people’s diet, lifestyle, and in homes and other indoor environments. For example, homes have tended to become warmer and, in this and other ways, much more appealing to cohabitation by dust mites, a real enemy of asthma sufferers. All these can act as asthma triggers. Cinemas and theatres can also surprisingly act as asthma triggers for some people. Research carried out recently found low levels of bacteria and moulds on carpets and seats, but high concentrations of cat allergens; presumably brought in on the clothes of members of the audience. Maybe get a DVD next time!