Asthma is a chronic long-term condition, which can be defined as a reversible constriction of the airways. The exact cause is still not completely understood but is thought to be associated with the production of immunoglobulin E (IgE) antibodies in response to allergens. It involves localised airway inflammation, bronchial hyper-responsiveness leading to bronchoconstriction, which results in intermittent airflow obstructions and the symptoms of asthma.

Asthma most commonly presents with one or more of the following symptoms. Symptoms are typically worse in the early morning and evening, and are precipitated by exercise, allergen exposure and cold air.

• Wheeze
• Breathlessness
• Chest tightness
• Cough.

Key facts

• There are 5.4 million people in the UK receiving treatment for asthma (1.1 million children and 4.3 million adults)
• The NHS spends around £1 billion a year treating and caring for people with asthma
• The UK has one of the highest prevalence rates of asthma in Europe
• On average, there are three deaths a day from asthma, two of which are preventable. Evidence shows that people with an asthma action plan are four times less likely to be admitted to hospital because of their asthma.