Damp and mould in your home doesn't just look unsightly - it can also be a health hazard, particularly if you're allergic to mould spores. Abi Jackson reports on a rising problem.

Whether it's a few pesky patches in the corners of the shower or around window frames, or ghastly black tides spreading up the living room walls, lots of people notice some degree of damp and mould in their homes.

The key cause of mould is moisture. This can be moisture in the air through poor ventilation or because you've been drying clothes indoors, as a result of leaky windows and pipes, or because external walls are in need of repair, or even after a one-off flood.

Modern and clean homes aren't immune - wherever there's moisture, mould and damp can be an issue. Not only can it be deeply unpleasant to live with and tricky to fix, it's also a potential health hazard.

Hollywood actress Brittany Murphy's untimely death in December 2009 highlighted just how dangerous mould can be. Though pneumonia and anaemia were cited as primary causes of the 32-year-old's death, toxic mould in her home was also noted as a possible factor.

Thankfully, cases like this are rare. There are hundreds of thousands of types of mould and the majority do not cause serious problems. However, damp and mould in UK homes could be affecting the health of countless people - who might not even be aware of the link.

"This is particularly the case for people who may be allergic to mould spores," says Lindsey McManus, deputy CEO of the charity Allergy UK. "But a lot of people don't realise they're allergic, or they may know they're allergic to certain things in their home, like dust mites or animal fur, but might not have made that link with mould too.

"Just a little bit of mould gives off millions of spores and can cause a reaction," she adds.

Symptoms are mostly respiratory and include being bunged up and congested, as well as itchy, puffy eyes, sneezing and a runny nose. It might feel like you've had a cold or sinusitis that just keeps on lingering, but the key difference is that with an allergy, you won't have had that initial 'unwell' phase, perhaps with a fever/high temperature, that occurs with viral infections.

"Sometimes, when you've had a cold, these symptoms do linger," notes McManus, "especially if you've been very bunged up. But with an allergy, you don't tend to have that bout of feeling very unwell to begin with - often with a cold you'd have felt very grotty for a few days - it's just the steady, lingering symptoms, and it could be all year round."

In some cases, mould allergy could worsen skin symptoms, like eczema too, and McManus notes that it may be a trigger for existing conditions like asthma and hay fever.

"People with hay fever know they've got hay fever, but they might not always know what they're actually allergic to. And somebody with asthma might generally have their symptoms under good control, but might not be making the link with damp in their home being a problem.

"The symptoms might be very low-grade for some people, they might just feel a bit bunged up and puffy-eyed when they're at home, to the other end of the extreme where it's really triggering severe asthma attacks."

If you experience these symptoms and have noticed damp and mould in your home, it's important to mention it to your GP, says McManus, as they might not automatically make the link.

If there's a chance you could be allergic to mould, your GP can refer you to a specialist for tests - after looking at your clinical history and the pattern of symptoms.

"As with any allergy, there's no cure, as such," McManus explains. "It's just a case of removing and avoiding whatever it is that you're allergic to. But some people may require treatment too, like antihistamines, nasal sprays or steroids in some cases."

Allergies aside, mould can be problematic for other people, too, particularly those who are in vulnerable groups, like babies, the elderly or people with weakened immune systems, due to other health conditions or medication.

Healthy people may be good at battling off mould spores, but they can get into the airways and sinuses, and cause more serious fungal infections that linger and are tricky to shift. People with chronic lung illnesses could be particularly affected.

Though damp and mould can be problematic at any time of year, it tends to worsen during the colder months, especially when people are keeping their windows closed, cranking up the central heating, drying laundry inside and condensation increases.

Tackling severe damp and mould problems might include having an expert to assess your property and pinpoint exact causes, and tackling these might involve spending some money. This is why it's a particular issue for people who are renting.

A recent YouGov/Shelter survey revealed that over a third (35%) of families who are renting have a damp problem. Almost one-in-five said they were living with a leaky roof or windows.

Students are also a high risk group, as student housing often tends to be in a poor condition.

Renters shouldn't have to put up with problematic damp. It's important that the issue's raised as soon as possible, and there are also things that people can do to help prevent and combat the problem.

"We know that there's a huge problem with rental accommodation [and damp]," says McManus. "Don't be afraid to speak up - there is support out there.

"And if you are concerned about symptoms you're experiencing, tell your GP."

Allergy UK has these tips for managing damp in your home:

:: Moulds flourish in damp environments, so prevent growth by keeping rooms well ventilated, with windows slightly open.

:: Thoroughly cleaning your kitchen, bathroom and utility room will help prevent mould growth.

:: Do not hang wet clothes inside or over radiators.

:: Clean mould from window frames and always remove condensation.

:: Keep houseplants to a minimum and change the topsoil regularly.

:: Do not use humidifiers.

:: It is essential to empty, clean and dry the water reservoir of dehumidifiers daily.

:: Use allergy bedding covers to protect you from mould spores.

:: Carpet harbours house dust mites and mould spores. Choose an Allergy UK approved flooring. If you need to keep your carpet, use a vacuum with HEPA filtration.

:: Using an air purifier in the bedroom can help to trap airborne allergens.

:: If you rent your home and feel that damp might be damaging you or your family's health, you should first contact your landlord. If you have further problems you should contact your local council.

:: For further information and advice visit www.allergyuk.org