Inflammation of the airways causes asthma, but the reasons for this lifelong respiratory condition are still not fully understood.
5.4 million people in the UK receive treatment for asthma.
Someone with asthma may not experience symptoms until they experience an asthma trigger, such as airborne irritants or chest infections.
Risk factors for developing asthma include:
- Genetics: Asthma can run in families and the risk of having asthma is higher if one or both parents have it
- A family history of allergic conditions, such as hayfever, eczema or a food allergy.
- Having bronchiolitis lung infection during childhood
- Exposure to second-hand cigarette smoke in childhood, or the mother smoking while pregnant
- Premature birth or needing a ventilator at birth
- Low birth weight
- Viral infection causing adult onset asthma
- Occupational asthma may develop after being exposed to irritants at work
- Modern day living, housing, diet, environmental pollution and a more hygienic environment may also be asthma causes, according to Asthma UK.