Asthma triggers

Some people are much more likely than others to develop allergies, such as asthma, hay fever and eczema. Certain ‘triggers’, such as pollens, household cleaners or pets, can cause an allergic response.

What can trigger asthma?

Many things can make asthma worse. Keep a list of your triggers when you discover them, and discuss them with your GP or asthma nurse.

Environmental triggers include:

  • Animal proteins, such as house dust mites, animal hair and cat saliva. Read more about pet hygiene if you have asthma.
  • Household cleaners and sprays can have an irritant effect, which can trigger asthma. Strong perfume can do the same.
  • Mould spores, which are released from trees at the end of the year, or in damp housing.
  • Pollens, including trees and grass.
  • Traffic fumes.
  • Weather and changes in temperature.

Other triggers include:

  • Some people with asthma find that exercise triggers their asthma symptoms. However, exercise is good for most people, including people with asthma.
  • Emotions. Negative emotions can act as a trigger, possibly for the same reason that exercise is a trigger. Your respiratory rate (the rate of breathing) increases, which means that you take in more air.
  • Hormones. A small number of women with asthma find that changes in their hormone levels can be a trigger. This may be worse before menstruation.
  • Medicines. In a few people, asthma is triggered by medicines containing salicylates, such as ibuprofen and some other anti-inflammatory drugs. It may also be triggered by beta-blockers, a type of drug prescribed for some people with cardiac disease, anxiety, hypertension, angina and glaucoma. If you have asthma, be cautious of taking ibuprofen (which may be sold by the brand name, Nurofen) or beta-blockers. Your GP, asthma nurse or pharmacist may be able to suggest an alternative.
  • Smoking.
  • Viral infections. A cold, the flu or other respiratory infections can make asthma worse.  

Visit the Asthma UK website to find out more about asthma triggers.

Find out more about living with asthma.

Page last reviewed: 30/06/2014

Next review due: 30/10/2016


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