Mould and damp-building illness: should I be tested?

Health effects of damp and mouldy buildings

Damp and mouldy buildings can genuinely affect your health. Good research supports this. People in damp homes or workplaces have a higher risk of breathing symptoms. This includes worse asthma, allergy symptoms, and cough. This is more common if you already have asthma or allergies. Rarely, heavy mould or dust exposure can cause a lung reaction called hypersensitivity pneumonitis. This causes fever, cough, and shortness of breath after exposure. It needs prompt medical care. If your symptoms are mainly breathing-related and connect to a specific damp space, that fits this picture well. If you have widespread symptoms, like fatigue and joint pain, with no clear breathing symptoms, mould exposure is a less likely cause. Fixing the dampness is the most effective step, alongside treating your specific symptoms.

"Mould illness" / "CIRS" (chronic inflammatory response syndrome)

Not a recognized medical diagnosis — here’s what it usually means and what to ask about instead.

You may have heard the terms 'mould illness' or 'CIRS,' short for chronic inflammatory response syndrome. This idea says hidden mould causes widespread symptoms like fatigue, brain fog, and joint pain. Some clinics offer urine tests for mould toxins, plus symptom checklists, to diagnose it. Health authorities have raised real concerns about this approach. There is no approved test for mould toxins in urine, and no level predicts illness. Mould toxins also show up in the urine of healthy people from ordinary food. In one investigated case, a urine result led to costly building testing that found no mould problem. Your symptoms are real and deserve investigation. Mould can genuinely worsen asthma and allergies (see the main mould page). But widespread symptoms like fatigue and joint pain usually have a different, treatable cause.