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    Causes and triggers of asthma

    On this page
    1. What causes asthma?
    2. Occupational asthma
    3. What triggers asthma?
    4. What is the best way to manage asthma triggers?

    Asthma is a very common long-term condition in which small tubes in the lungs (bronchi) become inflamed and sensitive. When these tubes come into contact with certain triggers that irritate them, the airways narrow and the muscles in the lungs tighten. The lungs also produce more mucus, and the combination of these three things leads to coughing, wheezing, breathlessness and a tight chest. In severe cases, a sudden onset of these symptoms (known as an asthma attack) can be life-threatening.

    Luckily, asthma is a fairly easy condition to manage on a daily basis with the use of the correct medications. Another important part of asthma management is learning about specific triggers. If you are affected by asthma, read on to find out more about the triggers and causes of asthma.

    What causes asthma?

    It’s not known precisely what the causes of asthma are, but it’s worth saying that asthma causes and asthma triggers are not the same thing. The causes of asthma are what lead someone to develop the condition in the first place. Asthma triggers, meanwhile, are environmental or lifestyle factors that exacerbate the existing condition and cause symptoms by irritating the airways.

    Asthma is thought to be caused by a variety of things, including genetics, environmental factors and early illness. Risk factors which could lead someone to develop asthma include:

    • a family history of asthma or allergies such as hay fever
    • suffering bronchiolitis (a lung infection) as a child
    • early exposure to tobacco smoke
    • mother who smoked during pregnancy
    • premature birth
    • low birth weight

    Occupational asthma

    Most risk factors for asthma relate to genetics, birth or early childhood meaning it’s difficult to avoid developing asthma in most cases. However, asthma can also be caused in adulthood from working in certain careers.

    Occupational asthma is asthma that is caused by substances you are exposed to at work. These can include flour and grain dust, wood dust, certain chemicals, car fumes, and animal dander. Occupations that carry a risk of asthma include paint sprayers, bakers, nurses, vets or animal handlers, chemical workers and timber workers.

    If you are regularly exposed to a substance like the ones listed above, your airways can become allergic to it, causing asthma symptoms every time you come into contact with it. In other cases, the substance may simply be an irritant that causes your airways to swell and tighten when it enters your lungs.

    What triggers asthma?

    In people with asthma, the airways of the lungs are sensitive and easily inflamed. This means when they are easily irritated by substances that they come into contact with. These substances are known as asthma triggers and will be different for everyone who suffers from asthma.

    The most common substances that trigger asthma are:

    • pollen
    • dust mites
    • animal fur or feathers
    • cigarette smoke
    • pollution or fumes
    • foods containing sulphites
    • mould or damp

    Not all triggers come in the form of a specific substance. Asthma can also be triggered by existing allergies, certain kinds of medication (in particular non-steroidal anti-inflammatories such as aspirin and ibuprofen), certain weather conditions, respiratory tract infections such as cold and flu, and even emotional states such as feeling stressed.

    For a more extensive list of asthma triggers, consult Asthma UK.

    What is the best way to manage asthma triggers?

    Getting to grips with asthma triggers takes time, but it’s important to monitor how symptoms are affected by certain foods, environments, substances, weather conditions, emotional states, or activities. Asthma sufferers should try to keep on top of their symptoms by monitoring them every day and measuring their peak flow (how much air they can blow out of their lungs). If they notice that their peak flow has decreased, this can be a sign of the condition worsening, or of an oncoming asthma attack.

    The most important thing is to stick to the recommended treatment course and use the medicated inhalers which have been prescribed. Nearly all asthma sufferers will be prescribed a reliever inhaler, which is used to ease the symptoms of coughing, wheezing and breathlessness by opening the airways.

    Preventer inhalers can also be used. These inhalers keep asthma symptoms under control and usually contain a corticosteroid which helps to reduce the inflammation and sensitivity of the airways. Relievers are only used when asthma symptoms flare up, whereas preventers should be used at least once a day.

    To learn more about asthma or if you would like to order reliever or preventer inhalers, visit our asthma treatment page at our online asthma clinic.

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