What is asthma?
Asthma is a disease of the airways – the breathing tubes that carry air into our lungs. Sometimes it is harder for a person with asthma to breathe in and out, but at other times their breathing is normal. Asthma is a long-term (chronic) disease.
Although there is currently no cure, with the right knowledge and good management, most people with asthma can lead full and active lives.
In this section
- Who develops asthma?
- What causes asthma symptoms?
- What are asthma triggers?
- What is an asthma flare-up?
- Over 2.5 million Australians have asthma – about 1 in 10 adults and about 1 in 9 or 10 children.
- Asthma and allergies are closely linked. Asthma is more common in families with allergies or asthma, but not everyone with asthma has allergies.
- Adults of any age can develop asthma, even if they did not have asthma as a child.
- Some people have asthma during childhood, but later have very few or no symptoms as adults.
- Many preschool children who wheeze do not have asthma by primary school age.
- Indoor and outdoor pollution (including moulds, gases, chemicals, particles and cigarette smoke) can increase the risk of developing asthma.
- Athletes can develop asthma after very intensive training over several years, especially while breathing air that is polluted, cold or dry.
The most common symptoms of asthma are:
- wheezing – a continuous, high-pitched sound coming from the chest while breathing
- shortness of breath – a feeling of not being able to get enough air
- a feeling of tightness in the chest
- coughing – alongside other symptoms.
You do not need to have all of these symptoms to be diagnosed with asthma.
Noisy breathing, such as a rattling sound, is common in healthy babies and preschoolers. This is not the same as wheezing and does not mean the child has asthma.
Many people think they have asthma only when they have asthma symptoms. In fact, the airways are sensitive all the time and most people with asthma have permanently irritated (inflamed) airways when not taking regular preventer treatment. From time to time, the airways tighten or become constricted so there is less space to breathe through, leading to asthma symptoms.
Asthma causes three main changes to the airways inside the lungs, and all these can happen together:
- the thin layer of muscle within the wall of an airway can contract to make it tighter and narrower – reliever medicines work by relaxing these muscles in the airways
- the inside walls of the airways can become swollen, leaving less space inside – preventer medicines work by reducing the inflammation that causes the swelling
- mucus can block the inside of the airways – preventer medicines also reduce mucus.
- Asthma symptoms can be triggered by different things for different people. Common triggers include colds and flu, allergies, and cigarette smoke.
Triggers can cause the airways to become narrow and inflamed, leading to asthma symptoms. Avoiding triggers, if possible, can help to control asthma. Anything that causes a reaction can set off your asthma symptoms.
These triggers differ between individuals. Over time, you will get to know which circumstances can make your asthma get worse. Some can be avoided altogether while others you will need to plan for.
Common triggers include:
- respiratory infections, such as colds and flu
- cigarette smoke
- allergy-related triggers, e.g. house dust mites, pollens, pets or moulds
- weather, e.g. cold air, change in temperature, thunderstorms
- work-related triggers, e.g. wood dust, chemicals, metal salts
- irritating substances breathed in the air, such as bushfire smoke
- certain medicines, e.g. aspirin, some blood pressure drugs
- stress and high emotions, such as crying
Exercise is another common trigger, but this can usually be managed by warming up properly and taking some extra asthma medication before you begin.
- Triggers - factsheets
- Sensitive Choice website (for approved products and services that may benefit people with asthma and allergy).
An asthma flare-up is when asthma symptoms start up or get worse compared to usual. The symptoms won’t go away by themselves and need treatment.
These flare-ups can happen quite quickly (e.g. if you are exposed to smoke) but they can also come on gradually over hours or days (e.g. if you get a cold).
The term ‘asthma attack’ is confusing because it means different things to different people – from a bout of wheezing after running for the bus through to being admitted to hospital for asthma.
An asthma flare-up can become serious if not treated properly, even in someone whose asthma is usually mild or well controlled. A severe flare-up needs urgent treatment by a doctor or hospital emergency department.