Mold can cause many health effects. For some people, mold can cause a stuffy nose, sore throat, coughing or wheezing, burning eyes, or skin rash. People with asthma or who are allergic to mold may have severe reactions. Immune-compromised people and people with chronic lung disease may get infections in their lungs from mold.

There is always some mold around. Molds have been on the Earth for millions of years. Mold can get in your home through open doors, windows, vents, and heating and air conditioning systems. Mold in the air outside can be brought indoors on clothing, shoes, bags, and even pets.

Mold will grow where there is moisture, such as around leaks in roofs, windows, or pipes, or where there has been a flood. Mold grows on paper, cardboard, ceiling tiles, and wood. Mold can also grow in dust, paints, wallpaper, insulation, drywall, carpet, fabric, and upholstery.

Page last reviewed: September 15th, 2021
Click here to see the full CDC Article. 

Molds are very common in buildings and homes. Mold will grow in places with a lot of moisture, such as around leaks in roofs, windows, or pipes, or where there has been flooding. Mold grows well on paper products, cardboard, ceiling tiles, and wood products. Mold can also grow in dust, paints, wallpaper, insulation, drywall, carpet, fabric, and upholstery.

The most common indoor molds are Cladosporium, Penicillium, and Aspergillus. We do not have precise information about how often different molds are found in buildings and homes.

Page last reviewed: August 11th, 2020

Click here to see the full CDC Article. 

Mold is found both indoors and outdoors. Mold can enter your home through open doorways, windows, vents, and heating and air conditioning systems. Mold in the air outside can also attach itself to clothing, shoes, and pets can and be carried indoors. When mold spores drop on places where there is excessive moisture, such as where leakage may have occurred in roofs, pipes, walls, plant pots, or where there has been flooding, they will grow. Many building materials provide suitable nutrients that encourage mold to grow. Wet cellulose materials, including paper and paper products, cardboard, ceiling tiles, wood, and wood products, are particularly conducive for the growth of some molds. Other materials such as dust, paints, wallpaper, insulation materials, drywall, carpet, fabric, and upholstery, commonly support mold growth.

Page last reviewed: August 11th, 2020

Click here to see the full CDC Article.

Exposure to damp and moldy environments may cause a variety of health effects, or none at all. Some people are sensitive to molds. For these people, exposure to molds can lead to symptoms such as stuffy nose, wheezing, and red or itchy eyes, or skin. Some people, such as those with allergies to molds or with asthma, may have more intense reactions. Severe reactions may occur among workers exposed to large amounts of molds in occupational settings, such as farmers working around moldy hay. Severe reactions may include fever and shortness of breath.

Page last reviewed: August 11th, 2020

Click here to see the full CDC Article.

People with allergies may be more sensitive to molds. People with immune suppression or underlying lung disease are more susceptible to fungal infections. Individuals with chronic respiratory disease (e.g., chronic obstructive pulmonary disorder, asthma) may experience difficulty breathing. Individuals with immune suppression are at increased risk for infection from molds. If you or your family members have these conditions, a qualified medical clinician should be consulted for diagnosis and treatment.

Page last reviewed: August 11th, 2020

Click here to see the full CDC Article.

Inspect buildings for evidence of water damage and visible mold as part of routine building maintenance, Correct conditions causing mold growth (e.g., water leaks, condensation, infiltration, or flooding) to prevent mold growth.

Inside your home you can control mold growth by:

• Controlling humidity levels;
• Promptly fixing leaky roofs, windows, and pipes;
• Thoroughly cleaning and drying after flooding;
• Ventilating shower, laundry, and cooking areas.
  

Page last reviewed: August 11th, 2020

Click here to see the full CDC Article.

• Keep humidity levels as low as you can—between 30% and 50%–all day long. An air conditioner or dehumidifier will help you keep the level low. Bear in mind that humidity levels change over the course of a day with changes in the moisture in the air and the air temperature, so you will need to check the humidity levels more than once a day.
• Use an air conditioner or a dehumidifier during humid months.
• Be sure your home has enough ventilation. Use exhaust fans which vent outside your home in the kitchen and bathroom. Make sure your clothes dryer vents outside your home.
• Fix any leaks in your home’s roof, walls, or plumbing so mold does not have moisture to grow.
• Consider not using carpet in rooms or areas like bathrooms or basements that may have a lot of moisture.

Page last reviewed: August 11th, 2020

Click here to see the full CDC Article.

After a hurricane or major flood, you may have to live in a home with mold in it. This could last for weeks, if you have nowhere else to go, or even months, if your whole community was affected. If you have to stay in a moldy home, you need to take steps to reduce your exposure to mold.

If you have asthma, COPD, or if you are immune-compromised you should not stay in a moldy home, or even be there while it is being cleaned.

• Spend less time in your home. Stay with friends or relatives as much as you can until your home is dried and cleaned up. If you can, shower and wash your hair at their home. If the weather is good, spend more time outdoors. During the day, visit libraries, malls, and other public places.
• Seal off the mold. Use plastic tarps to seal off moldy rooms in your house until they are cleaned.
• Don’t spread mold. When you go into a moldy room take off your shoes before you walk through the rest of your house. If you can, change your clothes.
• Create a separate sleeping area. If you have to sleep in a home with mold, seal off the cleanest room for sleeping with plastic tarps and always leave your shoes outside the room. Shower and wash your hair before you go to bed. Avoid wearing moldy clothes in this room and don’t carry things from other parts of the house into the room. Open a window to let fresh air into this room if you can.
• Use air conditioners and fans wisely. If your home has a whole-house HVAC system, don’t turn it on until it has been inspected—it could spread mold.If your HVAC is ok, don’t keep your home too cold because that could lead to more dampness and mold growth.
  If your HVAC isn’t working or if you don’t have one, open windows to let in fresh air. Try to pick windows away from moldy debris piles outdoors. Use exhaust fans in the kitchen and bathroom. If you use a portable fan, put it in a window or door blowing out. Never point fans at moldy surfaces—that will spread the mold.
  
• Clean, throw away, or seal moldy items. Wash and dry, or throw away, moldy bedding, towels, clothing, and draperies. If you have moldy papers you cannot throw away, dry and seal them in a bag until you can dry and clean them.

Page last reviewed: September 15th, 2021

Click here to see the full CDC Article.