Mold can cause health problems, especially for people with allergies or asthma. To prevent mold in your home, take action to remove it yourself or call in a professional if necessary.
Mold is likely to be found in the darkest, dampest areas. Mold is more than a cosmetic problem, it can damage your home and contribute to health problems.
Let’s take a look at the types of mold you’re most likely to find in your home, the potential effects on your health, and how to get rid of mold.
Mold is an organism that is part of the fungus family. It grows both indoors and outdoors.
Outdoors, fungi are an important part of the ecosystem. They help break down plant and animal matter. When mold grows inside, it can sometimes be problematic. It can cause allergies and infections in some people.
Types of fungus
Multiple types of mold can grow in the same area. You can’t always tell the difference between types of mold without testing. Fortunately, you don’t need to know the type of fungus to get rid of it.
The most common indoor molds are:
- Cladosporium. This mold is brown, green or black. Cladosporium grows in both warm and cool locations. It is most commonly found on wood, carpets or fabrics, and in heating and cooling ducts.
- Penicillium. This fuzzy mold is blue, green or yellow. It is often found under carpets, in basements and in insulation, especially if there has been water damage.
- Aspergillus. Aspergillus is green, white or gray with dark spots and a powdery appearance. This type of mold does not require much ventilation. It thrives in fabrics, walls, attics and basements, as well as dry food.
There are other molds that are not as commonly found indoors as the ones mentioned above, but you can still find them in your home. These include:
- Alternaria. This fuzzy fungus is white with black spots. It tends to grow in fabrics and wallpaper, near windows and air conditioners, and in bathrooms and kitchens.
- Aureobasidium. This mold is pink with black spots. It is most commonly found on wood, walls, caulking and grouting.
- Stachybotry’s papers. This green-black mold, also known as black mold, grows on things with a high cellulose content. It is usually found on paper, fiberboard, and drywall (drywall).
- Trichoderma. This fungus is creamy white but turns green when it releases spores. It is commonly found on wood, windows, and in bathrooms and kitchens.
Mold in the house does not necessarily make you sick, but it can cause certain health problems.
Touching or inhaling mold spores can cause allergy symptoms, such as:
- runny nose and congestion
- eye irritation
- to sneeze
- a sore throat
- skin rash
- irritation of the lungs
Mold exposure is not an emergency for most people. However, you should let your doctor know if you have a health condition that puts you at greater risk for complications and you believe you are experiencing symptoms of a yeast infection. Read more about complications of mold exposure below.
Mold can be black, white, mottled, or just about any color. It can look powdery, fluffy or velvety.
If you notice a stain and aren’t sure if it’s just an old stain or a dirt stain, here’s how to tell if it could be a sign of a mold problem:
- It has a musty, earthy smell.
- There is a nearby source of moisture, but not much light.
- You see warping, cracking or peeling of the material it grows on.
- A drop of bleach will lighten the color in a minute or two.
- Unchecked mold will continue to grow. Dirt and old stains do not.
How common is mold in buildings?
Mold is common in homes and buildings.
A 2017 study found mold in every public building surveyed, with an average of about 14 cases of mold per building.
How does mold get into the house?
Outdoor fungi release tiny spores that float through the air. These spores can enter your home through:
- vents for heating and air conditioning
- clothes and shoes
Once mold spores enter, they can grow under the right conditions.
Mold spores grow in areas with moisture, such as:
- in sinks, bathtubs and showers
- near leaking pipes
- around windows
- in basements, crawl spaces and attics
They can be attached to a variety of materials, including:
- ceiling tiles
How do you know if you have a mold problem?
Anytime you see or smell mold in your home, it’s a problem. All types of mold can potentially cause health problems and should be removed.
Mold starts out as a small spot but grows quickly. You will usually notice it early on unless it is in a remote location.
Mold is everywhere and everyone breathes in mold spores. Mold allergies occur when your immune system overreacts to certain types of mold, which your body considers an allergen. This can result in symptoms such as sneezing and nasal congestion.
Not all molds cause allergy symptoms. The most common types of mold that cause allergy symptoms are:
You may be more likely to develop a mold allergy or experience mold allergy symptoms if you:
- have a family history of allergies
- work or live in a building with humidity above 50 percent or poor ventilation
- work or live in an environment that has been flooded, has leaking pipes, or is otherwise exposed to extreme humidity
- work in a job where you are more likely to be exposed to mold, such as:
- wood millers
If you think you have symptoms of mold exposure, let a doctor know. It can be difficult to determine whether mold, another condition, or some type of allergy is causing your symptoms. Your doctor may offer you skin or blood tests to determine if you really have a mold allergy.
Treatments and preventive steps for mold allergies may include:
- medications, including corticosteroid nasal sprays and antihistamines
- allergy shots, which may be especially appropriate if you experience severe symptoms year-round
- controlling humidity in the home, including:
- keeping the humidity below 50 percent with a dehumidifier
- regular cleaning of damp areas, such as basements and bathrooms
- keep humid areas well ventilated
- quick repair of any leaks
What Helps Mold-Induced Nasal and Sinus Symptoms?
Some types of over-the-counter (OTC) medications can help relieve mild to moderate symptoms associated with mold exposure. These medications include:
If you have more severe symptoms, contact a health care professional.
Most people may only experience an allergic reaction or allergy-like symptoms after exposure to mold. More rarely, mold can cause more serious health problems in some people with certain risk factors.
Most people regularly inhale mold spores without experiencing any health complications. However, people with certain health conditions may be at risk for a lung infection or other infections from breathing in certain types of mold.
Examples of fungal-related infections include:
You may be at higher risk for these diseases if you have conditions such as:
In people with asthma, an allergic reaction to mold can trigger an attack. They may need inhalers to manage symptoms.
Exposure to a large amount of mold can sometimes cause a more serious reaction known as hypersensitivitypneumonia. This type of exposure is usually due to occupational or workplace hazards rather than exposure to mold in your home.
Black mold exposure is rumored to be linked to health problems such as memory loss and headaches. This was thought to be because black mold spores release toxic compounds called mycotoxins. However, experts generally agree that black mold is not linked to an increased risk of specific health problems.
A 2017 study found no evidence that exposure to black mold causes health problems. Another 2019 study highlighted that airborne mycotoxins are not associated with disease.
In many cases, you can remove household mold yourself. Mold can be removed with:
- commercial products
- soap and water
- a bleach solution of no more than 1 cup of bleach per 1 gallon of water
Before you start:
- Open any windows.
- Wear safety goggles, non-porous gloves, and a face mask or N95 respirator.
- Never mix other cleaners or ammonia with bleach as this can create toxic fumes.
Use a brush to scrub mold off surfaces and make sure you get it all. Porous materials, such as carpeting, furniture, and ceiling tiles, may need to be discarded. Do not paint or caulk until you are sure all mold is gone.
Find a professional contractor experienced in safe mold removal if:
- there is a large amount of mold or it is difficult to reach
- you have had severe water damage
- you are at high risk for mold spores symptoms
Mold spores are everywhere and are part of the world we live in. It’s impossible to get rid of mold completely, but there are ways to make your home unsuitable for mold. This includes taking the following steps:
- Fix water leaks immediately. Clean up excess water and use fans to dry the area.
- Repair or replace windows that leak or sweat, as moisture can build up on the frame and sill.
- Maintain a humidity level of 50 percent or lower in your home with air conditioners and dehumidifiers. Replace filters and maintain air conditioners and furnaces as recommended.
- Do not install carpeting in rooms such as bathrooms, laundry rooms, or basements.
- Keep your home well ventilated. If possible, exhaust fans should vent to the outside. Use exhaust fans or open windows when showering or bathing.
- Use cleaning products that kill mold. Wipe the tiles clean and let the shower curtains dry.
- Do not leave wet towels or clothes in a pile or in a hamper or washing machine.
- Make sure the water drains away from your home.
- Use mold inhibitors in wall paints. Make sure surfaces are dry before applying paint.
Mold in your home doesn’t always cause health problems, but it should always be removed. Mold can cause damage to your home and can lead to irritations in the:
If you have a mold allergy or a chronic lung condition such as asthma, you are at risk for more serious symptoms and complications.
A few chores around the house can make it more difficult for mold to grow indoors. If you have mold spots in your home, you can take steps to remove the mold yourself. If it’s a big job, or if you have breathing problems, a professional contractor can safely remove mold and make any necessary repairs.