Is Mould Dangerous? Health Risks Explained

Damp and mould aren’t just unsightly — they can affect your health, which is why the law treats serious cases so seriously. This guide explains the risks in plain terms, who is most vulnerable, and when to act.

Important: this is general information, not medical advice, and health points need verifying against current NHS guidance. If you’re worried about your health or symptoms, speak to a GP or call NHS 111.

Can mould affect your health?

Yes. Living with damp and mould is associated with effects on the airways and breathing, including respiratory problems, infections, allergic reactions and worsening asthma. The seriousness of the Awaab Ishak case — which led to Awaab’s Law — was a tragic illustration of how dangerous prolonged exposure can be, especially for a young child.

Who is most at risk?

Some groups are generally more vulnerable to the effects of damp and mould:

Babies and children
Older people
People with asthma, allergies or respiratory conditions
People with a weakened immune system or certain other illnesses

This is exactly why housing hazard assessments under HHSRS focus on the most vulnerable likely occupant, not an average adult.

Symptoms to be aware of

Commonly reported effects of damp and mould exposure include:

coughing and wheezing,
a runny or blocked nose,
sore throat and eye irritation, and
worsening asthma symptoms.

If you or someone in your home has symptoms you’re worried about, seek medical advice from a GP or NHS 111.

What about “toxic black mould”?

“Black mould” is a common description rather than a single species, and online claims about it can be exaggerated. The sensible approach is not to fixate on colour but to treat any persistent or significant mould as a problem to remove — and to fix the moisture causing it. See how to get rid of mould on walls.

What to do about it

Don’t ignore it. Clean small areas promptly and safely (mask, gloves, ventilation).
Fix the cause so it doesn’t return — usually condensation or another form of damp.
Protect the vulnerable — prioritise rooms used by children, older people or anyone with a respiratory condition.
Get help for serious or recurring mould — an independent damp and mould surveyor can find the cause.

Renting? Damp and mould affecting your health is a serious matter your landlord must act on — see your rights as a tenant, and, if it has caused harm, how much compensation for damp and mould.

Frequently asked questions

Is mould dangerous to your health?

Damp and mould can affect health, particularly the airways. They are linked to respiratory problems, infections, allergies and asthma, and the risk is higher for some groups. Always check current NHS guidance for health specifics.

Who is most at risk from mould?

Babies and children, older people, and those with asthma, allergies, respiratory conditions or a weakened immune system are generally more vulnerable. This is why housing hazard assessments focus on the most at-risk occupant.

What are the symptoms of mould exposure?

Reported effects include coughing, wheezing, a runny or blocked nose, sore throat and eye irritation, and worsening asthma. If you're worried about symptoms, speak to a GP or NHS 111.

Is black mould more dangerous than other mould?

'Black mould' is a common description rather than a single species, and any persistent mould in the home is worth removing. Rather than focusing on colour, treat significant or recurring mould seriously and fix the cause.