There may be danger lurking in your home.

Mold can be a nuisance as well as a health hazard. Black spots and dusty patches on the walls may indicate that your home has mold. According to the U.S. Department of Agriculture, mold is a fungal growth that forms and spreads on various kinds of damp or decaying organic matter and it can pose respiratory problems for you and your family.

Nicholas Money, a fungal biologist and science writer from Miami University, says that the microscopic fungi that grow in homes can trigger asthma and other allergies. Money says that mold is found everywhere, and despite its bad reputation, it does serve a useful purpose by fertilizing the planet with fresh nutrients when it rots organic materials.

However, when mold soaks right through drywall in your home and the mold colonies grow into large brown or black patches, you have a problem, says Study Finds. If the area is smaller than a pizza box you may be able to clean it yourself. But if the mold is more extensive, you'll probably have to replace the drywall. The best way to prevent mold from forming in your home is to repair leaks and avoid flooding.

If you suspect you may have a mold problem, there are experts who can help. An indoor air quality specialist can test your home by measuring the concentration of airborne microscopic mold spores. High concentrations of spores can trigger allergies. The expert will also take samples of the air both inside and outside the home to compare the levels of spores present. If the levels are higher inside than outside, chances are mold is growing in the home.

Money says that mold presents three problems. Firstly, it is unsightly and smelly. Secondly, it can trigger asthma, allergic rhinitis, or hay fever. And lastly, molds can contain mycotoxins. According to the World Health Organization, mycotoxins are poisons that can cause a variety of adverse health effects and pose a serious health threat to humans when inhaled.

Money says that the toxic black mold called Stachybotrys was once linked to lung bleeding in infants. It grows on drywall that's been soaked in water and produces a wide range of mycotoxins. While it's unlikely that adults will inhale enough of the spores to cause health issues, the developing lungs of infants and children are more at risk.

"This is why it is important to limit mold growth in homes and address the sources of moisture that stimulate its development," he says. The U.S. Environmental Protection Agency has a helpful guide on how to clean up residential mold problems and how to prevent mold growth.