After months of rain lashing parts of the country, chances are if you're living along the east coast you've already experienced mould this season.

It can affect clothing, shoes, furniture, walls, and many other parts of the home.

While mould can be a headache to clean and keep away, it can also be toxic and extremely harmful to your health.

With the La Niña weather system causing flooding and catastrophic damage to homes in Queensland and northern NSW, some people have even been forced to leave their properties instead of dealing with mould on a larger scale.

Here's everything you need to know about mould, its effects and how to contain it.

What causes mould?

Mould is part of the fungi group that also includes mushrooms and yeast.

It often grows in poorly ventilated spaces including kitchens, bathrooms, and laundries.

Dust and dirt can also encourage mould growth.

It can range in colour from green, white and brown and is attracted to surfaces including roofs, windows, or areas where there has been flooding or rising damp.

Mould can grow on paper, cardboard, and wood, as well as wallpaper, carpet, fabric, and upholstery.

Large infestations of mould can be identified by a smell, which is often described as a "musty" smell.

According to Gerard Murtagh, from cleaning company MouldMen, mould in the home is caused by wet or dampness, lack of ventilation, and humidity.

"Due to the wet weather, we're seeing more and more properties that are being flood affected or water damaged," he says.

"We're seeing a lot of houses that have got water ingress through them. Sometimes it's because the gutters are filling up so quickly with water, they just can't get the water away from the home.

"They then go back over into the eaves or feet and then that water can flow into the house."

How do you stop mould growing?

Removing the dampness and humidity is the key to stopping mould, as it needs moisture and nutrients to grow.

When it's a sunny day, allow as much sunlight as possible into the area.

But when it's wet and humid, try putting your air conditioner on a dry cycle or using a dehumidifier.

Don't pack your furniture too close to the wall — leave room for airflow.

Use absorbent beads to soak up extra moisture in wardrobes and other areas.

Plant lovers should know reducing the number of indoor plants in your home can stop mould forming, according to the Queensland government.

How do you remove mould?

A mix of three parts vinegar to two parts water is helpful in removing mould, according to the Queensland government.

Clove oil is often recommended but can cause surfaces to discolour or cause allergies.

The Queensland government also suggests methylated spirits at a ratio of 70 per cent and 30 per cent water, or a tea tree oil solution.

Any cloths used with mould removal should be discarded to avoid the spread of spores and using a broom or brush to remove the mould is not recommended as it can have the same effect.

If the mould is more difficult to remove, a diluted bleach solution can help but make sure the area is well ventilated and protective clothing is worn if cleaning with bleach.

Mr Murtagh says those who tackle mould at home should make sure they are wearing the right protective gear including gloves and face masks.

"If mould growth is the same size as your hand or a dinner plate, then definitely tackle it yourself and you can do that easily with a domestic cleaner," he says.

"If it's bigger than that, there's sometimes a bigger issue going on and you might need the advice of a cleaning professional to come out and help with that."

Mr Murtagh says if the mould is more widespread, getting to the root cause of the problem is the key.

"The first thing you need to do is make sure you're addressing the moisture issues," he says.

"So mould is a by-product of an increase in moisture either through water or through ventilation, or the humidity.

"We always say the first thing you have to do is try to dry out the area. So if it's a water leak, obviously fix the water leak and dry it out.

"If it is humidity or the ventilation issue then you need to either open up your house and ventilate, which is very difficult now on days that are wet or when they start to cool down.

"So we recommend the use of dehumidifiers or the use of air conditioning systems on dry cycle."

Is mould bad for you?

Mould produces tiny spores, which are carried in the air and can cause serious health problems if inhaled.

Bond University medical professor Natasha Yates, who also works as a GP on the Gold Coast, says the persistent damp conditions for months on end have led to an influx in related health problems in Queensland's south east.

"Our body, within minutes, will start to react and give us those symptoms and it's really hard to get rid of … a cough, runny nose, headaches, wheezing, general exhaustion, and fatigue.

"It can be a reaction to mould, an allergic reaction, or even an infection from the mould itself."

She says people who have had COVID are more susceptible to mould.

"COVID makes you unwell and predisposes you to getting a secondary infection for at least the week or two after you suffer from it," Dr Yates says.

For people with asthma, inhaling mould spores may cause an asthma attack.

Those suffering from other respiratory diseases or people with immunosuppression are also at higher risk of infection.

How widespread is the mould problem?

Mr Murtagh says he has "never had more phone calls" than right now.

"Recently, we were taking 1,000 enquiries a month. Now, it's over 5,000.

"And we're expecting that through what we call mould season — usually May through to October, November — because it's been so wet, we'll be seeing an increase in the amount of mould that is already present.

"Now we've got these cooler days and continued wet weather, we're expecting that to potentially go up to 20,000 enquiries per month around Australia."

Dr Yates says she has seen significant numbers of patients with mould-related illness and allergies, believed to be from recent rainfall and floods.

"But we're seeing a huge number of people on the Gold Coast presenting with what we believe are mould-related symptoms."

Can I claim mould removal on my insurance?

While providers may not insure for mould-related illnesses, some will assist in removing mould, improving ventilation, and replacing damaged items.

According to insurance law firm Berrill and Watson, most insurance policies do not cover mould with the majority explicitly stating they do not cover damage if the primary cause of it is mould.

However, many policies will pay if the mould damage is secondary to an insured event like storm damage, water leaks, or flooding.