Fuzzy mould - banner

Mould and damp

Watch out for mould and damp at home. It could make your asthma worse.

Health advice > Asthma triggers

“If you’ve noticed your symptoms getting worse speak to your GP or asthma nurse. They can support you to manage your asthma well and update your asthma action plan,” says Dr Andy Whittamore, Asthma UK’s in-house GP.  

What is mould?

Why damp and mould are a problem for asthma

What to do if you’ve got damp or mould at home

Top tips to prevent damp and mould at home

Mould spores when you’re out and about

What is mould?

Mould is a type of fungus that grows in damp places. If you’ve got mould at home, you’ll probably notice fuzzy black, white or green patches on the walls, ceilings or tiles. It might smell damp and musty.

Mould is more common in homes which need repairs like window frames fixed, or leaks sorted out. You might notice it’s more damp and mouldy in bathrooms or kitchens because of condensation from washing and cooking.

Why damp and mould are a problem for asthma

Living in a damp, mouldy home is not good for your asthma. Babies, small children, older people, and people with allergies are more likely to be affected.

  • Mould produces spores which can be breathed in. If you’re allergic to mould spores you might have symptoms like coughing, wheezing, sneezing or watery eyes. And it could trigger your asthma symptoms.

  • Damp and mouldy housing can put you more at risk of other things that can make your asthma worse like chest infections, colds and flu, and rhinitis.

  • Dust mites are more of a problem in homes that are damp and warm.

What to do if you’ve got damp and mould at home

If you think your home is damp, or you’ve noticed mould, it’s best to act quickly to sort out the problem before it gets worse.

You need to:

  • Deal with the damp - find out what’s causing the damp, such as leaks, or condensation from cooking, showering or drying clothes indoors.
  • Deal with the mould - don’t try and get rid of any mould by yourself if it triggers your asthma - ask a friend to help. And always get a mould removal specialist or builder in if the mould covers more than a square metre, or if it’s caused by problems with the building itself, or sewage.
  • Report any repairs or leaks, or problems with mould, if you’re renting. Shelter have information about talking to your landlord/landlady. You may also be able to get a housing assessment from your local council's environmental health department.

“If you need your reliever inhaler three or more times a week, see your GP or asthma nurse, whether it’s mould or something else making your asthma worse,” says Dr Andy. “They can help you get back in control of your symptoms.” 

5 Top tips to prevent damp and mould at home

1. Open windows and doors so air can move around. But be cautious on high pollen or pollution days if these are triggers for you.

2. Try to avoid drying clothes indoors. If you have nowhere else to dry them, open a window if you can.

3. Use extractor fans in the kitchen and bathroom or open a window when cooking or after a shower.

4. Close the door of the room you’re in if you’re cooking or showering - to prevent condensation in other rooms

5. Try to keep your home at a good background temperature so it never gets too cold - at least 15 degrees in all rooms.

“Some people find that de-humidifiers help to dry the air and prevent damp and mould. But you need to get the setting right or they can leave the air too dry and make you cough,” says Dr Andy. 

Mould spores when you’re out and about

It’s not easy to avoid mould spores altogether when you’re out and about, so make sure you’re taking your preventer inhaler every day as prescribed. This means you’re less likely to react to any of your asthma triggers, including mould.

But you could also cut your risk by:

  • avoiding areas such as woodlands, parks, or gardens in the autumn when there are more mould spores around
  • going for park or country walks on cold, dry, windy days - avoid warm, damp weather when there’s more risk of mould spores
  • clearing up in the garden so fallen leaves or rotten plant materials don’t build up, and be careful turning the compost heap when you're gardening, as there can be spores there too. 

“Make sure you carry your reliever inhaler with you at all times so you’re ready to deal with asthma symptoms quickly if you get them,” says Dr Andy.


Last updated January 2020

Next review due January 2023

Did you find this information helpful?

Step 2

Would you use our information again or recommend it to a friend?
Please choose the option that best describes you

Asthma action plans keep all your personal triggers and medicines tips in one place. Download one now to fill in with your doctor or nurse.