Asthma triggers

Which asthma triggers affect you? Find out more about why certain triggers can bring on symptoms, and how to reduce your risk.

Asthma triggers

Asthma symptoms can have a range of triggers, such as respiratory tract infections – particularly infections affecting the upper airways, such as colds and the flu

What’s an asthma trigger?

A trigger is anything which starts your asthma symptoms or makes your asthma symptoms worse. You may find, for example, that being around cats or dust sets your symptoms off. Or it might be pollen, cold weather, or being near someone who’s smoking. What triggers your asthma symptoms may be different to what triggers someone else’s.

It’s possible to have several triggers and sometimes it’s difficult to work out what your triggers are.

If your asthma symptoms are caused by more than one trigger at the same time, it could cause a stronger reaction - for example, if you have a cold and you come into contact with a cat. This could explain why sometimes triggers do cause symptoms and why sometimes they don’t.

Latest research shows there are two key things you can do to reduce the effect of asthma triggers:

1. Keep your asthma as well managed as possible

This means you’ll have less of a reaction if you do come into contact with any triggers. The best ways to do this are:

  • Take your preventer medication exactly as your doctor has prescribed. It’s specially designed to work away in the background every day to help reduce your body’s reaction to triggers you meet in your daily life.
  • Use a written asthma action plan to help you identify when your asthma needs extra help and what to discuss with your GP or asthma nurse.
  • Get your asthma reviewed regularly, so you and your GP or asthma nurse can talk about your asthma in general, and your triggers - and can make sure you have the correct medicines and that they’re doing the best possible job for you.
It’s impossible to avoid all triggers but you can cut your risk of developing asthma symptoms when you’re exposed to them.

Dr Samantha Walker |  Deputy Chief Executive and Director of Research and Policy, Asthma UK

2. Get to know which triggers affect you

If you understand which things trigger your asthma you might be able to avoid them. If you can’t avoid them, you can speak to your GP or asthma nurse about the best ways to help stop them causing asthma symptoms.

  • Have you got obvious triggers? Often it’s obvious which things trigger your asthma - for example, when your symptoms start within minutes of coming into contact with a cat or dog.
  • What are your other triggers? Sometimes it’s not easy to pinpoint exactly what triggers your asthma. This is because some triggers are invisible (such as grass pollen); you may have more than one trigger; and sometimes you may have a delayed reaction to a trigger.  A bit of extra detective work may be needed - try keeping a diary of activities and symptoms to help you spot any patterns.