Asthma is caused by inflammation of the airways and can develop at any age. In the UK, 5.4 million people are currently receiving treatment for asthma. That is 1 in every 12 adults and 1 in every 11 children. Asthma in adults is more common in women than men.

When you come into contact with something that irritates your lungs, known as a trigger, your airways become narrow, the muscles around them tighten and there is an increase in the production of sticky mucus (phlegm).

The symptoms of asthma include:

  • Feeling breathless
  • A tight chest, like a band tightening around it
  • Wheezing, which makes a whistling sound when you breathe
  • Coughing, particularly at night and early morning

A trigger is anything that irritates the airways and brings on the symptoms of asthma. These differ from person to person and people with asthma may have several triggers. Once you know your asthma triggers, you can try to avoid them.

Triggers include:

  • Airway and chest infections – Upper respiratory infections, which affect the upper airways, are often caused by cold and flu viruses
  • Allergens – Pollen, dust mites, animal fur or feathers
  • Airborne irritants – Cigarette smoke, chemical fumes and atmospheric pollution
  • Medicines – The class of painkillers called non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin and ibuprofen
  • Emotional factors – Asthma can be triggered by emotional factors, such as stress or laughing.
  • Foods containing sulphites – Sulphites are naturally occurring substances found in some food and drink. They are also sometimes used as a food preservative. Food and drinks high in sulphites include concentrated fruit juice, jam, prawns and many processed or pre-cooked meals.
  • Weather conditions – A sudden change in temperature, cold air, windy days, poor air quality and hot, humid days
  • Indoor conditions – Mould or damp, house dust mites and chemicals in carpets and flooring materials
  • Exercise – Sometimes, people with asthma find their symptoms are worse when they exercise.
  • Food allergies – Although uncommon, some people may have allergies to nuts or other food items, known as an anaphylactic reaction

* The contents of this condition is for information purposes only.