Learn
Learn about asthma
Switch between a plain-language explanation and a clinical one at any time — the same topics, two levels of depth.
What asthma is
Asthma is something that happens inside your airways — the little tubes that carry air in and out of your lungs. Think of them like bendy straws.
When something bothers those straws, they get puffy on the inside, the muscles around them squeeze tight, and they fill up with sticky goo. The straw gets narrow, so air has a hard time getting through — and that can make a whistling sound.
Asthma doesn't go away completely, but with the right medicine most kids and grown-ups barely notice it on a normal day.
Symptoms
Asthma symptoms come and go. Most people feel totally fine in between — that's exactly why taking the everyday medicine still matters, even on good days.
Common symptoms
- Wheezing — a whistling sound when breathing out
- Coughing, especially at night or early morning
- Shortness of breath or feeling out of breath easily
- A tight or heavy feeling in the chest
- Waking at night because of breathing
- Needing the reliever inhaler more than twice a week
Causes and triggers
Nobody catches asthma and nobody causes it by doing something wrong. It comes from a mix of genes passed down in families and things around us when we're very young.
Once someone has asthma, certain things — called triggers — can wake it up and cause symptoms. Everyone's triggers are a bit different, so keeping a simple diary helps find yours.
Frequent triggers
- Allergens: pollen, dust mites, animal dander, mold
- Irritants: tobacco and wood smoke, pollution, strong scents
- Infections: colds, flu, RSV, COVID-19
- Exercise, especially in cold dry air
- Weather changes and thunderstorms
- Strong emotion, laughter or stress
- Some medicines, including aspirin and beta-blockers
Risk factors
Asthma is more likely to show up if a mom, dad, brother or sister has asthma, eczema or hay fever. Living around cigarette smoke, dirty air or a damp, moldy house also makes it more likely.
Myths vs. facts
Wrong information about asthma can actually hurt people — usually because it convinces them to stop taking their everyday medicine.
Setting the record straight
- Myth: children always grow out of asthma. Fact: symptoms often ease in the teens but can return in adulthood.
- Myth: asthma medicine is addictive. Fact: inhalers are not addictive; needing the reliever often means the preventer needs reviewing.
- Myth: people with asthma should avoid sport. Fact: regular exercise improves lung fitness and control.
- Myth: asthma is psychological. Fact: it is a physical inflammatory condition, though stress can trigger symptoms.
- Myth: you only need medicine when you feel unwell. Fact: preventers work by keeping inflammation low every day.
- Myth: moving to a dry climate cures asthma. Fact: triggers travel, and new environments bring new ones.
Diagnosis
A doctor or nurse will ask what your breathing has been doing, whether anyone else in the family has asthma, and what seems to set it off. They'll listen to your chest and usually ask you to blow into a machine.
Very young children are often diagnosed just by watching their symptoms and seeing if asthma medicine helps, because blowing tests are tricky before about age five.
Treatments
Most asthma medicine is breathed in through an inhaler, so it goes straight to the airways using just a tiny amount.
A preventer is used every single day, even when you feel fine, to keep the airways calm. A reliever is used to quickly open up tight airways when symptoms happen. Some people use one inhaler that does both jobs — always follow your own asthma plan.
Treatment building blocks
- Daily preventer (inhaled corticosteroid)
- Reliever for symptoms (SABA or ICS-formoterol)
- Add-on long-acting bronchodilators
- Leukotriene receptor antagonists such as montelukast
- Allergy treatment, including immunotherapy in selected cases
- Biologic therapy for severe asthma
Managing asthma in daily life
The same condition behaves differently at school, at night, on holiday or during sport.