Health: Meet the expert on asthma causes and management

Photo / Supplied

Element magazine talks to Dr Bob Hancox, Asthma Foundation medical director and respiratory specialist?, about the symptoms, causes and triggers of asthma and how to manage it.

What is asthma?

A disease involving the narrowing of the 'airways' (the bronchial tubes) causing wheezing and breathlessness.
The underlying problem is usually that the airways are inflamed; often this is a form of allergic inflammation.
Because the airways are inflamed they react to triggers, meaning narrower inflamed airways get even narrower - setting off an asthma attack.

Symptoms

Wheezing - a whistling noise heard when breathing, breathlessness, coughing, tight chest. These symptoms come and go, varying in severity.

At what age do you develop asthma?

Asthma can develop at any stage. Most people develop it in childhood, but around 75% of children who have asthma before they are seven will have grown out of it by the time they are 16.
Babies can get 'wheezy bronchitis'. It's very difficult to know whether this is asthma or whether they're just getting lots of chest infections. Many babies will grow out of it, but symptoms will persist in some and become asthma.

How is it caused?

No-one knows for sure. We understand that it is a mixture of genetics and environmental exposures, but it is still unknown how they interact to cause asthma.?Research has shown that boys are more likely to get asthma than girls, but are more able to grow out of it, meaning women are more likely to have asthma than men.
For new adult sufferers asthma could be related to their job. Some occupations are associated with causing asthma, such as jobs dealing with dust, like bakers, woodworkers, those with exposure to certain chemicals e.g. isocyanates in car paints, people working in aluminium smelters.
Even so, in most cases of adult-onset asthma we can't identify the cause.

What are the triggers?

We need to distinguish between what triggers asthma and the causes. If I had asthma and I got a cold, my asthma might deteriorate. That doesn't mean that the cold caused my asthma - it just made my symptoms worse.

Key triggers include: The house dust mite - probably the most common allergen and asthma trigger in New Zealand. Dust mites are found in most houses due to the damp, warm environment. Their presence is not related to the cleanliness of the house. Also pollen - like privet and grass, cats and dogs, cold air and exercise.

How to manage your asthma?

Obviously don't smoke and avoid smoky places. Smoke is an irritant to the airways and children with asthma don't need to be exposed to it.
Keep your house warm and dry through insulation, heating and double-glazing - living in a cold, damp house makes asthma symptoms worse.?
Talk to your doctor about treatment. If you get symptoms on a regular basis you need to be on a mix of inhalers to keep your asthma under control.
People with frequent symptoms should have a preventer inhaler, to prevent symptoms from coming on.
Have an asthma action plan, which you can get from the Foundation website, so you can understand your asthma and take control of symptoms before they become a real problem.
Visit the asthmafoundation.org.nz for more information.