If you have a cough or a cold that won't go away, it might not just be a sign winter is coming in.

Experts say it could be a horrifying sign of a secret cockroach infestation - and you may have no idea they are in your house.

The Food Standards Agency (FSA) say there are four different breeds of the pest common to Britain.

How will I know if I have an infestation?

As the critters are so secretive - scurrying away at the first sign of light - you might not even know your home is harbouring them.

The scurrying beasts try to seek sanctuary indoors as the colder months set in, invading your walls, cupboards, pipes, sinks and floor cavities.

They are secretive creatures who shy from the light, so if they’re well hidden you’d be none the wiser.

Some of the signs you may be sharing your home with cockroaches include lingering odour that's ‘musty’.

This odour is smeared on any object the cockroaches are in contact with.

You may see brown or black cylindrical droppings which are around 2mm in length.

You may also see irregular shaped smear stains. These marks usually appear on horizontal surfaces and at wall-floor junctions where cockroaches scuttle along.

What are the symptoms?

Wherever cockroaches roam, they leave traces in the form of their saliva, faeces and shedded body pieces.

These particles contain specific proteins, or allergens, that can cause allergies and trigger a variety of pretty grim symptoms.

Property protection expert Ranjen Gohri, of 24|7 Home Rescue, has urged Brits not to mistake the tell-tale signs of a cockroach horde for symptoms of a common cold or flu.

Symptoms include a chronic stuffy nose, ear and sinus infections, itchy eyes and nose, a persistent cough and wheezing.

He said: “If you’re bunged up and your sinuses are feeling infected, you might assume you’re just coming down with the flu, particularly at this time of year and with autumn approaching.

“But it’s vital you don’t become complacent. Because some of the medical symptoms associated with cold and flu also bear all the hallmarks of a cockroach infestation.

“And while the UK population of cockroaches does reduce in size in the winter months, this is also when the insects swarm inside homes looking for somewhere hot and humid to hide.

“You need to be on your guard.”

What are the risks?

They are also known to spread bacteria such as salmonella and E. coli, which can cause serious food poisoning.

They can also trigger dysentery, gastroenteritis, asthma and eczema.

How do I get rid of them?

The key to keeping them at bay is cleanliness and good home maintenance.

  • Be thorough, make sure your kitchen floors are clean, check your sinks, counters and cookers. Sweep behind appliances regularly.
  • Avoid piles of newspapers, laundry or magazines as they are also attracted to clutter - and that includes accumulated dirty dishes.
  • Seal all food containers and ensure any food bins are sealed too.
  • Keep a clean microwave, mop up any spills, and empty the toaster of crumbs.
  • Once your pet has been fed in the evening, remove their food bowl so there are no traces of food left.
  • Cockroaches also need access to water, so fix any leaks you may have in the house.

The most common type of cockroach in the UK is the ‘German cockroach’, which will eat almost anything, including leather, books, packaging, plastic and any leftover food you leave on the floor.

A single pair of German cockroaches can produce 10,000 offspring in a year.

Autumn and winter is when the hard-shell pests tend to move indoors from their outside summer dwellings.