What is asthma?
Children with asthma have inflammation in the small airway passages (bronchi) of their lungs. This makes their airways sensitive to triggers. Triggers are the things that bring on asthma attacks. When children come into contact with triggers, the muscles in the walls of their airway passages tighten up.
When this happens, children get less air into and out of their lungs. This causes wheezing, coughing, chest tightness and uncomfortable breathing.
Causes of asthma: genes, inducers and triggers
Children with asthma probably get genes from their parents that make it more likely that they'll get asthma too. This is called genetic predisposition.
If you, your child's other parent or other family members have asthma, eczema, hay fever or allergies, there's an increased chance your child will also have asthma.
Early in life, something switches on a child's asthma for the first time. This thing is called an inducer. The asthma inducer might be a viral infection, an allergen or something in the environment that irritates the child's airways.
Once a child's asthma has been switched on, triggers can cause acute asthma attacks. These triggers vary from child to child.
The most common trigger is a viral infection, usually the common cold. Other triggers include pollens, exercise, changes in the weather, cold air, cigarette smoke, pollution, house dust mites and pets.
Children with asthma react to asthma triggers by wheezing, coughing and becoming short of breath.Exposure to smoke during pregnancy, or to second-hand and third-hand smoke in childhood, can lead to asthma in children who have a genetic predisposition to it.
Tests for asthma
Most children don't need any special tests for asthma. Doctors usually diagnose asthma on the basis of your child's medical history and by examining your child.
Children with more severe asthma, or who have frequent asthma attacks, might need special breathing tests or very occasionally an X-ray. These are often arranged by a paediatrician or respiratory specialist.