Asthma is a condition that leads to narrowing of the airways of the lungs. Symptoms include wheeze, cough and difficulty breathing.

Illustration by Dr Greta File. Property of KidsHealth.

Graphic of lungs and airways showing normal airways and airways in someone with asthma


Key points about asthma

  • asthma is a condition that leads to narrowing of the airways of the lungs
  • symptoms include wheeze, cough and difficulty breathing
  • common asthma triggers are colds (viruses), exercise, dust, pollens and cigarette smoke

What is asthma?

Asthma is a common breathing condition. It affects the small and medium-sized airways (bronchi) in the lungs. 

In asthma, your child's airways are inflamed and there is:

  • swelling of the airway wall
  • an increase in mucus or phlegm
  • tightening of the muscle in the airway wall  (see the image at the top of the page)

These changes cause narrowing of your child's airways. This leads to wheezing, cough and difficulty with breathing.

Wheezing is a musical, whistly sound that children make, usually when breathing out. It can also happen when they breathe in. The sound comes from the chest, not from the nose or throat. 

Why do some children have asthma?

One in 4 children in New Zealand will have asthma at some time during childhood. 

It is not clear why some children have asthma when others do not.

Asthma in children is more likely if:

  • a mother smoked during pregnancy 
  • a child has eczema, hay fever or allergies
  • there is asthma in the family - parent, brother or sister
  • one or both parents have an allergic condition such as asthma, hay fever or eczema

Modern Western lifestyle may play a part in the rise in asthma that has happened over the last few decades. Changes in housing, diet and a more hygienic environment may contribute. Outdoor environmental pollution may make asthma symptoms worse but it does not actually cause asthma. Experts continue to study the reasons for the increase in asthma. 

What causes an asthma attack?

Children with asthma have airways that are sensitive and react to certain triggers.

Some children have asthma all year round. Others may only have it in certain seasons or situations. 

Triggers which cause an asthma attack include:

  • viruses - for example, a cold, with a runny nose
  • things people are allergic to such as pollens, moulds, pet hair and dust-mites
  • cold or humid weather, or a change in the weather
  • exercise
  • emotions such as anxiety and excitement
  • air pollutants, such as cigarette smoke

Keep a symptom diary and a record of possible triggers

Asthma symptoms and triggers may differ from child to child and from time to time. It is useful to know your child's triggers. Keep a symptom diary and keep a record of possible triggers.

Make sure your child's environment is smoke-free

Make sure your child's environment is smoke-free, wherever they happen to be. Asthma increases in children whose parents smoke. Tobacco smoke also triggers asthma attacks and makes a child's asthma more severe than it would otherwise be. Many environmental factors contribute to asthma; cigarette smoke is one that you can avoid.

If you want to give up smoking:

Keep your house warm and dry

Aim to keep your house warm, dry and well-insulated.  

Read about keeping your home warm and dry

Could my child have asthma?

You should see your doctor and ask about asthma if your child:

  • wheezes and coughs with a cold (virus)
  • wheezes and coughs after exercise
  • wheezes and coughs during the night
  • cannot keep up when they are running around with children of the same age
  • says they are out of breath or breathless
  • complains they feel tired or ask you to carry them (depending on their age) when you go for a walk
  • does not run around as much as children of the same age

These are some of the symptoms of asthma in children. But, these symptoms may be due to other less common conditions. Talk to your doctor.

If my child does have asthma

Every child with asthma needs an action plan. If your child has asthma, ask your family doctor for an asthma action plan. The plan will tell you how to prevent asthma attacks and how to manage them when they happen.

Action plans

See a child asthma action plan in te Reo Māori (PDF, 574 KB)

See a child asthma action plan in English (PDF, 593 KB)

See a child asthma action plan in Samoan (PDF, 561 KB)

See a child asthma action plan in Tongan (PDF, 547 KB)

Online learning tool

You can use the Asthma + Respiratory Foundation NZ's online learning tool to learn more about how you can help children with asthma stay fit, healthy and happy.

Screenshot of Asthma + Respiratory Foundation interactive resource

Booklets to download

You can read the following translated booklets alongside the online learning tool above. 

Read a booklet about managing your child's asthma in te Reo Māori (PDF, 3.06 MB)

Read a booklet about managing your child's asthma in English (PDF, 3.59 MB)

Read a booklet about managing your child's asthma in Samoan (PDF, 3.05 MB)

How do I prevent my child from having asthma attacks?

Preventers help prevent asthma.

Not all children need preventer medicine. If your child is getting wheezy more than once a week, your family doctor may suggest a preventer medicine. Your child needs to take their asthma preventer every day, sometimes twice a day, even when they are well. Most asthma preventers are inhalers that you need to use a spacer with. Sometimes, your doctor may give you a preventer that is a tablet.  

    How do I treat my child's asthma attack?

    You will need to use the blue inhaler with a plastic tube called a spacer. 

    Photo of a blue inhaler and spacer

    Blue inhaler and spacer

    • give 2 puffs of the blue inhaler, one puff at a time, using the spacer, every 4 hours
    • for each puff of the blue inhaler, your child will need to take 6 breaths through the spacer

    If your child is still not improving:

    • you can give up to 6 puffs of the blue inhaler every 4 hours

    You need to take your child to your family doctor, or an after-hours clinic, or the hospital:

    • if you need to give the blue inhaler more often than every 2 hours - for example, every 60 or 90 minutes
    • if there is no improvement 30 minutes after giving 6 puffs of the blue inhaler

    Watch Lachlan show how to use your inhaler with a spacer (Asthma Waikato video).

    When should I seek urgent help for an asthma attack?

    Many children have only mild asthma. But be careful - it's possible for any child with asthma to have a severe, life-threatening attack.

    When to see a doctor urgently

    Keep your child sitting up and give them 6 puffs of the blue inhaler through the spacer and see a doctor urgently if your child has any of the following symptoms:

    • is breathing fast, wheezing and having to use extra effort to breathe
    • is breathless at rest
    • looks unwell
    • looks pale and is beginning to get tired
    • gets worse after beginning to get better
    • has trouble completing a sentence because of difficulty breathing
    • you are worried

    Check out the signs that your child is struggling to breathe

    When to seek emergency medical help

    In severe asthma it is usually better to dial 111 rather than drive your child in your own car to the hospital.

    Keep your child sitting up and give them 6 puffs of the blue inhaler through the spacer. Immediately dial 111 within New Zealand (use the appropriate emergency number in other countries) and ask for emergency medical help if your child:

    • has severe difficulty breathing
    • is too breathless to talk
    • is floppy and very tired
    • is becoming less responsive
    • has blue lips and tongue
    • has periods of stopping breathing

    In severe asthma, it is best to dial 111 rather than drive your child in your own car to the hospital.

    While you are waiting for the ambulance, keep giving your child 6 puffs of the blue inhaler through the spacer every 5 minutes.

    Will my child grow out of asthma?

    Asthma is a long-term condition. The majority of children with asthma have less troublesome asthma as teenagers. Symptoms can appear again in adulthood. If your child has severe asthma, it is more likely to continue or return in later life.

    Your child should learn about asthma and gradually take over responsibility for its management, as they become a teenager, with support from you.


    Photo of blue inhaler and spacer taken by KidsHealth team.

    This page last reviewed 02 May 2022.

    Call Healthline on 0800 611 116 any time of the day or night for free health advice when you need it