Asthma is a chronic lung condition that is characterized by difficulty in breathing. People with asthma have extra sensitive or hyper-responsive airways. During an asthma attack, the airways become irritated and react by narrowing and constructing, causing increased resistance to airflow, and obstructing the flow of the air passages to and from the lungs.
What triggers an asthma attack ?
The words “trigger factors”, or “triggers” of asthma are used for the things which can cause an attack in someone who already has asthma.
Many things seem to be able to bring on, or trigger, an asthma attack, and the causes and triggers vary greatly from person to person. Dogs and cats cause asthma attacks in some people. While for others, tobacco smoke, cold air, exercise and even laughing can trigger attacks too. Some people with asthma report that the asthma attacks are worse when they are upset, anxious or under stress. Some people get asthma if they take aspirin or other painkillers, and some get asthma from dusts or fumes at work.
Really bad asthma attacks, which force people to go into hospital, often happen after a virus infection of your nose or chest.
During an asthma attack, the airways become irritated and react by narrowing and constructing, causing increased resistance to airflow, and obstructing the flow of the air passages to and from the lungs.
But what causes asthma?
Why do some people develop asthma?
Why is asthma more common in the western world?
Asthma is not contagious. You cannot catch asthma from another person.
However, you can inherit the asthma tendency from your parents, although people with asthma should not worry about their future children on this score.
Studies show that children whose parents smoke are twice as likely to develop asthma as children of non-smoking parents. Also, children whose mothers smoked during pregnancy tend to be born with smaller airways, which greatly increases their chances of developing the disease.
The “westernised” environment and lifestyle in developed countries has a lot to do with the chances of whether a person will develop asthma or not.
Are overweight people more likely to get asthma, as is often suggested?
When talking about diseases, it is important to distinguish between causes and triggers.
A trigger is something which sets off an attack, but which does not make you asthmatic in the first place.
The “trigger factors”, or “triggers”, of asthma are used to describe the things which can cause an attack in someone who already has asthma.
But you hear these words used for the dog to which you may be allergic, or the cat, or the mould on the wallpaper which causes your asthma, or the pollen that cause your asthma, and even about house dust mites. Instead of calling these things causes, which is what they are, people call them “triggers”. They say that your cat is triggering your asthma.
This is a bit like calling an on-coming car the trigger for an accident.
Demoting causes, by calling them triggers, makes people think they are not so important, and that maybe they should just keep using their inhalers instead of making efforts to root out the cause of their asthma and remove these from their environment.
A cause is something without which an effect (such as asthma) will not happen. That is, a cause is something without which you would not be asthmatic. There may be more than one cause for an asthma attack.
Some research indicates that the symptoms of asthma may get worse when stomach acid rises up your gullet, a condition called gastro-oesophageal reflux disease, or GERD, or, more commonly acid reflux.
Acid reflux can cause painful heartburn which you can relieve with antacid medicines. That is, special medicines which neutralise the acid. Acid reflux happens mostly in people who are older and overweight. But it can happen in children and in all types of people.
In some studies, researchers have injected acid into the gullets of people with asthma, and it had a significant impact on their asthma and caused worse asthma symptoms.
These is also evidence to suggest that people who have asthma get acid reflux more often than people without asthma. This is probably because of the big pressure changes in the chest during breathing in people with asthma. These high pressures could force liquid to travel the wrong way up the oesophagus.
In these cases, asthma sufferers seem to lose out twice: they suffer from asthma and they may suffer from acid reflux more often than non asthma sufferers.
However, this is not the whole story. If acid reflux really was an important cause of asthma worsening, then treatments against acid reflux should make the asthma better, however, this is generally not the case.
Asthma is a chronic inflammatory disease that makes airways (bronchial tubes) particularly sensitive to irritants, and this is characterized by difficulty in breathing.
Asthma is a highly ranked chronic health condition in adults in most western countries, and it is the leading chronic illness of children.
Asthma cannot be cured, but for most patients it can be controlled so that they have only minimal and infrequent symptoms and they can live an active life.
However, there are quite a few illnesses which can mimic the symptoms of asthma, and lead to a misdiagnosis.
For example, vocal cord dysfunction syndrome can mimic an asthma attack.
Usually the problem with making a diagnosis of asthma is making it early enough.
However, sometimes in people who do have true asthma as well, difficulty in breathing can be caused by abnormal movements of the voice box during breathing. This can mimic a severe asthma attack so closely that a correct diagnosis is difficult.
But if this condition is recognised, then treatment will be much more appropriate.
There are quite a few other illnesses which can mimic the symptoms of asthma, though these are all very rare compared to asthma, and much rarer than vocal cord dysfunction
The cause of the inflammation which underlies most asthma in younger sufferers is one or more allergies.
More people in western countries suffer from allergies, compared to people in less affluent rural parts of the world, and allergy rates are on the increase.
There is a growing body of evidence which virtually proves that asthma is an environmentally induced disease. This raises the challenging possibility that we may be able to prevent asthma by altering our environment.
Treating asthma by removing the allergic cause can be very successful when the cause is easy to remove, as when the allergic cause is a dust or vapour inhaled only at work.
The same is true when the cause is a domestic pet such as a cat or dog, though reluctance to part with a loved pet commonly prevents success.
However, the commonest cause of asthma is allergy to house dust mites, and getting rid of mites sufficiently to make a big difference to asthma requires a major change in lifestyle of the sufferer and is expensive to achieve.
There may be future treatments which modify, abolish or diminish the allergy process in the body, and this is an area of considerable research.
There are two main types of medicines for the treatment of asthma:
Quick Relief Medicines: also called relievers, give rapid, short-term treatment and are taken when you have worsening asthma symptoms that can lead to asthma episodes or attacks. You will feel the effects of these medicines within minutes.
Long-Term Control Medicines: also called preventers, are taken every day, usually over long periods of time, to control chronic symptoms and to prevent asthma episodes or attacks. You will feel the full effects of these medicines after taking them for a few weeks. People with persistent asthma need long-term control medicines.
Drugs, such as those resembling two of our hormones, can help treat asthma. These two hormones are adrenaline (epinephrine in the USA) and hydrocortisone (a steroid).
There are also other drugs which help treat asthma. Whilst drugs can remove all your symptoms if you have mild asthma, people with more severe or long-standing asthma don’t get nearly such good results, so alternate medications are required.
Adrenaline (epinephrine) is pumped into our bloodstream when we have a sudden fright or emergency. It is the quick-acting hormone from the middle of the adrenal glands near our kidneys. It makes your pulse race, makes your heart thump, and readies your body for emergency action. In asthma, the medicines which resemble adrenaline quickly relieve asthma for a short time, and are called relievers.
The symptoms of Asthma include:
Coughing. Coughing in people with asthma is often worse at night or early in the morning, making it hard for them to sleep.
Wheezing. Wheezing is a whistling or squeaky sound when you breathe.
A tight feeling in the chest. This can feel like someone is squeezing or sitting on your chest.
Shortness of breath. Asthma sufferers often say they can’t catch their breath, or they feel breathless or out of breath. They feel like you can’t get enough air in or out of their lungs.
Episodes of wheezy difficulty in breathing.
Faster breathing or noisy breathing.
Narrowing of the air passages in the lungs and hence increased resistance to airflow.
Rapid and considerable changes in airway obstruction (peak flow variation >= 20%)
Frequent nocturnal episodes and low morning peak flow values
Significant reversibility with drugs which resemble adrenaline, the beta2 agonists
Significant reversibility with steroid drugs
Frequent occurrence of allergy
Inflammation of the air passages, characterised by eosinophils in the airway wall
Bronchial hyper-responsiveness to non-specific stimuli such as cold air or histamine.