Can cockroaches make you ill or trigger asthma?

They can. Cockroach droppings, saliva and shed skins are a well-known indoor trigger for allergies and asthma, and cockroaches walk through drains and bins before they walk over worktops. But chest pain and trouble breathing have many causes, and they need a doctor to look at them, not a guess from a forum or from us. So get the symptoms seen, and deal with the cockroaches at the same time. Both matter.

Chest pain, or struggling to breathe: call the emergency number where you live now. Do not wait to work out the cause.

What to tell your doctor

• Your symptoms and when they started. Cough, wheeze, tight chest, itchy eyes, a blocked nose, a rash.
• When they get worse. At night, in the kitchen, after cleaning, or when you are home rather than away.
• That you live with cockroaches, and for roughly how long.
• Any asthma or allergies you already have, and anyone else at home with symptoms.
• Every product you have used at home. Sprays and foggers can irritate airways too, so name them or bring the labels.

Your doctor can then decide whether an allergy test or an asthma check makes sense. If they confirm a link, a note from them also helps if you rent (more on that below).

How cockroaches affect health

• Allergens in the dust. Droppings, saliva, shed skins and dead cockroaches break down into household dust. For people who are sensitive to them, breathing that dust can set off allergy or asthma symptoms. Dead ones still count.
• Germs on food and surfaces. They pick up germs in drains, bins and rubbish and leave them where they walk. Throw away uncovered food they may have been on, and wipe surfaces before you cook.

None of this is a judgement on your home. Cockroaches turn up in clean homes too. They come for warmth, water and shelter.

Cut the allergens at home

1. Treat the cockroaches. Allergens keep building while they live there. For the small indoor German cockroach, the plan is gel bait, an insect growth regulator and monitor traps. Choose bait over sprays and foggers, which put product into the air you breathe. Follow the label.
2. Clean the dust out, damp. Wipe with a damp cloth rather than dry dusting or sweeping, which lifts dust into the air. A vacuum with a HEPA filter, if you have one, holds fine dust better. Start where droppings gather: droppings and egg cases shows what to look for, and is this cockroach poo helps you tell them from other specks.
3. Clean around the bait, not over it. Wiping it away undoes the treatment.
4. Take away food and water. Food in closed containers, dishes done at night, a lid on the bin, leaks fixed.
5. Wash bedding and soft toys on the hottest wash their care labels allow.
6. Keep cleaning after they are gone. The allergens stay in the dust after the last cockroach. Killing them is half the job.

Asthma at home: if you can, let someone else do the dusty cleaning and stay out of the room while they do it. Ask your doctor whether a mask makes sense for you. Keep bait and traps where children and pets cannot reach them.

If they come in from the garden

Cockroaches that live outdoors and wander in are often a different species from the German cockroach that breeds indoors. You still do not want them on your food. Check which one you have with our four cockroaches side by side. Then close the way in: gaps under doors, around pipes and vents, with door sweeps and filler. Sealing gaps shows how.

If you rent

Tell your landlord in writing, with dates, photos and what you have seen. Say it is affecting your health, and mention a doctor’s note if you have one. In many places a lasting pest problem in a rental is the landlord’s to fix, but the rules vary by country. Ask your council’s environmental health team in the UK, or the local housing authority, tenancy board or a tenants’ union elsewhere. How to document pests for your landlord and when the landlord will not act cover the next steps.