13 Types of Molds in Homes

You may think that mold occurs only in old and unkempt houses and buildings, but the truth is – mold can develop just about anywhere, even in new buildings and homes.

Some mold is not as harmful as other types, which can be hazardous to your health if left untreated.

Types of Mold

Mold is a living substance that grows in certain conditions and is often dangerous for human health. Typically, mold grows in darker and damper environments where the temperature range is between 60 to 80 degrees Fahrenheit, but it can occur just about anywhere – in your home, your office, and even in your car.

It is essential to recognize mold as well as know what the potential threats to your health can be from residing in a home that has mold.

Mold is a fungus. There are many mold species, but not all types of mold are harmful to humans.

In fact, some species of mold may actually be beneficial to us, like one type that produces penicillin. But other types can produce spores that can cause allergic reactions in people.

This article will detail the different types of mold and what you should do if you find them in your home or workplace. They are three main types of mold:


These types of mold are very allergenic. They may cause a bad reaction in people, like red eyes and itchy skin or even asthma reactions.


These types of molds are very dangerous for people with acute illnesses. Their spores may cause serious infections.


Toxigenic molds produce toxic elements that can make people sick. These toxins cause all sorts of health problems, from minor nuisances to life-threatening illnesses. These molds are also called “toxic molds”.

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How can mold affect human health?

Mold should be handled and duly removed as soon as it is identified as starting to develop. Some types of mold can be highly toxic and may cause serious and permanent damage to the health, depending on the type as well as the level of exposure to it.

Some people, like children, elderly people, and pregnant women, as well as those with chronic illnesses or weak immune systems,  are especially susceptible to developing mold-related health problems.

Here are some of the effects that mold can have on the human body and health:

It can cause mold sensitivity after prolonged exposure or trigger allergies and negative reactions in people with an existing sensitivity or mold allergies, including:

  • Chest and nasal congestion
  • Sore throat
  • Sneezing or coughing
  • Itchy, sore, watery, or dry eyes
  • Itchiness and skin irritation
  • Headaches

Some mold-related illnesses and infections are especially dangerous for people with COPD, other respiratory problems, or weak immune systems. Such people can develop infections of the lungs from exposure to mold.

Mold can also cause various respiratory health problems and conditions to otherwise healthy people as well. Exposure to some types of mold can cause wheezing, coughing, difficulty breathing, as well as asthma, or other respiratory diseases.

In people who already have asthma, exposure to some types of mold can trigger asthma attacks as well.

Some mold types produce dangerous toxins known as mycotoxins, which can be absorbed by breathing, as well as through the skin or through ingestion. Prolonged exposure to these toxins can cause serious health problems, including cancer, pulmonary fibrosis, pulmonary bleeding, blood, immune system disorders, kidney and liver problems, neurotoxicity, problems with pregnancy, heart problems, etc. digestive problems.

How to prevent the development of mold?

The right way to treat mold is to take preventive actions and prevent its development altogether.

Since most types of mold start developing as a result of dampness and water damage, it is essential to take care and fix any leaking or broken pipes in a timely manner, as well as dry off any wet surfaces and areas meticulously, clean the hard floors and carpets at home regularly, do regular checkups on your home, especially if you are moving into an old house and others.

One of the easiest ways to ensure that you don’t get into contact and breathe in any harmful toxins and spores released by the mold is to invest in a good-quality air purifier.

A good air purifier can capture and trap all kinds of mold spores no matter how miniature and microscopic they are from the air in your home and will keep them safely inside the filters of the unit and out of your lungs and of your bodies.

Some models of air purifiers on the market are a superb tool for removing mold spores from the air and keeping them away from the air that you breathe and from recontamination of your house.

What are the most common mold types which can be found in households?

It is best if you never encounter a mold problem in your home, but in some cases, mold can appear, and it is a good idea to know a little bit more about the most common household molds and how they can affect your health if left untreated.

Since mold is a fungus that can grow just about anywhere and is found around the globe, there a tens of thousands of different types of mold known to humankind. Some of them are not dangerous, while others can cause chronic and severe illnesses and health conditions.

Here are the main types of harmful molds which you may encounter in your house, car, or elsewhere where you and your family reside:

Allergenic molds – these can cause allergic reactions such as nasal congestion, wheezing, sneezing, coughing, skin irritation, and asthma attacks.

Pathogenic molds – these are especially dangerous for people who are already suffering from a chronic or acute illness.

Toxigenic molds: these are the molds that produce toxic substances that can cause serious and even fatal conditions to otherwise healthy people as well.

Here are the main types of mold which can be found in your home or workplace, which you should be aware of:


This is a toxigenic mold that starts up as a small and moist mold but then evolves into a fine powder. Acremonium can be grey, pink, orange, or white and can usually be found in window sealants, places where there is condensation from humidifiers, in drain pans, cooling coils, and others.

Exposure to this toxic mold can lead to damage and illnesses of the immune system, the bone marrow, and damage to other organs. Since it is a carcinogen, Acremonium can also harm the function of the brain.

It can grow along with other harmful molds such as Stachybotrys and create serious mold problems in homes and other properties.


Alternaria is one of the most common household molds. It usually appears in dimly lit or darker and damper areas like around the shower, bathtub, sink, or outside of the house. This mold type can trigger allergies and asthma attacks.


This is another very common mold type that thankfully is not that harmful to humans when its spores are inhaled. Some of the more severe reactions to Aspergillus spores can include allergic reactions, inflammation of the lungs, or other respiratory infections.


This mold type can grow on wooden surfaces, wooden furniture, wallpaper, painted walls, and caulk and around the windows. It is usually black and pink in color and appears like spots in some of these areas. It, too, is a common household mold and can cause allergic reactions as well as some more severe health problems.


This type of mold typically grows in drywall, which has undergone water damage. It has a cotton-like structure and a musty smell, which makes it easy to recognize. It can cause nail and skin infections and is particularly dangerous for people with compromised immune systems. It starts up as a white spot and evolves into grey, brown, and eventually into black color.


This is another allergenic mold type that is unique because it can grow both in warm and cold conditions.  It can grow in carpets, upholstery, old fabrics, wood floorboards, wooden furniture, and cupboards.

Cladosporium can cause allergic reactions to the skin, eyes, and respiratory system. Some of the side effects of exposure to this mold include skin lesions and rashes, lung infections, asthma, and sinusitis.


Penicillium is easy to recognize because of its blue or green coloring and its unique velvety texture. It can be found in carpets, insulation, ducting, mattresses, wallpapers, and other materials and furniture at home.

Penicillin spores in the air can cause asthma and pulmonary inflammations, as well as chronic sinusitis.


Fusarium is also capable of growing in colder conditions. It is both an allergenic and a toxigenic type of mold that can grow in carpets, wallpaper, other fabrics, and materials, usually after water damage.

Fusarium can also grow on compost and on food products and is pink in color. It can cause allergic reactions, skin infections, but prolonged exposure to this type of mold is known to cause more serious health problems, including brain abscess or bone infections as well. This mold spreads quite quickly, so if you notice it somewhere, make sure you check the rest of the property for signs of Fusarium as well.


This is an allergenic mold type that grows in thick white or grey colored patches. It grows pretty quickly and can often be found around air conditioners, ducting and HVAC systems where there are condensation and moisture. Damp old carpets can also develop Mucor mold.

This mold can cause respiratory problems and is especially harmful to people suffering from asthma or other respiratory illnesses.

In rare cases and after prolonged exposure to Mucor, people can develop Mucormycosis, which is a fungal infection of the lungs, sinuses and can even affect the brain.

Serpula Lacrymans

This mold usually grows outdoors, but it can also appear on some wooden surfaces inside as well. It is yellow in color.

Stachybotrys Chartarum

This is also known as the “black mold” and is a toxic type of mold that can cause various allergic reactions. It has a dark green or black color and a slimy texture, and a musty smell. It prefers cellulose materials such as cardboard, wood, hay, paper, or wicker to grow on.

This mold produces mycotoxins which can cause sinusitis, difficulty breathing, aches, and pain in the sinuses, headaches, and even depression. This mold is particularly harmful to children and can cause neurological problems as well as pulmonary bleeding, which is why this type of mold needs to be handled and removed immediately.


This is a mold that loves damp areas and can be found in damp carpeting, wallpapers, or on other surfaces.

It produces toxins known as mycotoxins, which can trigger allergic reactions, sinus infections.

It also causes the surfaces and materials of the building to rot and crumble and, if left untreated, can cause serious damage to the structure of your home as well.


Ulocladium is usually black in color and can be found in wet and water-damaged areas, such as walls with high condensation, basements, as well as in bathrooms, kitchens, and others.

Ulocladium can cause allergic reactions similar to hay fever, asthma, or skin irritations, as well as various mild to serious infections.

Final Words

Mold might sound scary, but the truth is there are ways to prevent it, as well as safe ways to stay away from exposure to mold spores and toxins.

It is essential to take preventive actions such as inspecting your home regularly, fixing any leaks in a timely manner, treating water damage properly, and using an air purifier in your home to remove the spores from the air and thus away from the air that you and your family breathe!