RELATED: 7 Cleaning Habits That Attract Spiders. Many people experience allergies in autumn, thanks to pollen and mold from decaying leaves. But if your symptoms—coughing, wheezing, and sneezing, in particular—tend to coincide with when your heating system turns on for the season, experts say it may be due to mold that’s circulating within your home. “This is the time of year my phone starts to ring off the hook,” Jeffrey C. May, principal of J. May Home Inspections and author of My House Is Killing Me: The Home Guide for Families with Allergies and Asthma, tells The New York Times. May explains that many homes provide ideal conditions for mold spores to grow, including its three main requirements—oxygen, moisture, and a food source. “Most people don’t even know they have a problem until they start getting sick,” he added. RELATED: If You’re Not Cleaning This Room, You’re Inviting Snakes to Your Home. Household mold can cause a range of health issues besides coughing, wheezing, and sneezing. You may also experience a runny nose or congestion, itchy eyes, skin rash, sore throat, headache, and more. “Some people, such as those with allergies to molds or with asthma, may have more intense reactions,” explains the Centers for Disease Control and Prevention (CDC). “Severe reactions may include fever and shortness of breath,” their experts add.ae0fcc31ae342fd3a1346ebb1f342fcb Mold can grow inside the ducts of your heating system, but May tells the Times that you’re most likely to find it inside the coil and fiberglass lining of your HVAC unit. That’s because these areas are most likely to collect dust and are easily exposed to moisture. “I’ve seen coil linings that were completely infiltrated by mold,” says May. Depending on the state of your HVAC unit, individual parts may need to be cleaned or replaced to fix the problem. For more health news sent directly to your inbox, sign up for our daily newsletter. If your symptoms persist after your HVAC system has been given the all-clear, it may be time to inspect the rest of your home for mold and address any problem areas you find. In particular, the CDC recommends controlling humidity levels, fixing leaky roofs, windows, and pipes, cleaning and drying after any flooding incidents, and properly ventilating high-humidity areas, such as your bathroom, laundry space, and kitchen. Additionally, it pays to be thoughtful about the many ways that mold can infiltrate your space in the first place. “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 and can be carried indoors,” explains the CDC. They recommend checking for mold in the most highly susceptible materials of your home. “Wallpaper, insulation materials, drywall, carpet, fabric, and upholstery, commonly support mold growth,” the health authority notes. RELATED: If This Body Part Hurts You at Night, See Your Doctor.