Types, causes and symptoms
Understanding what asthma is, how it is caused and how it affects you is your first step
towards managing it and living your life in the best possible health.
What is asthma?
Asthma is a condition that affects your airways – the small tubes that carry air in
and out of your lungs. When you have asthma, coming into contact with something
that irritates your airways (an asthma trigger) causes the muscles around the
walls of the airways to tighten so that they become narrower. The lining of
the airways also becomes inflamed and starts to swell. Sometimes sticky mucus or
phlegm builds up which can narrow the airways even more.
Asthma reactions can be triggered by one of a number of factors, including something
you are allergic to such as pollen or dust, or they can happen when you are under stress.
Causes of asthma
There are a number of potential causes of asthma:
- Family history – you are more likely to develop asthma if you have a family history of asthma, eczema or allergies
- Modern lifestyles – for example, changes in housing and diet and a more hygienic environment may have contributed to the rise in asthma over the last few decades
- Allergens in the home such as house dust mite or animal fur
- Foods – certain foods or chemicals contained in foods can trigger asthma attacks
- Smoking – children whose parents smoke are more likely to develop asthma and smoking during pregnancy significantly increases the risk of a child developing asthma
- Environmental factors – pollution can make asthma symptoms worse and may cause asthma to develop in some people
- Infections – adults may develop asthma after a viral infection
- Workplace irritants – for example, chemicals, may lead to a person developing asthma at work, which is known as occupational asthma
Symptoms of asthma
People with asthma may suffer from a variety of symptoms including coughing, wheezing,
shortness of breath and tightness in their chest.
View graphic depictions
of asthma
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