Mold Symptoms and Health Risks: What You Should Know

Mold Symptoms and Health Risks in Damp Buildings

Mold symptoms and health risks can vary from one person to another. For example, some people may notice eye, nose or throat irritation, coughing, wheezing or skin irritation around damp or moldy areas. Others may have no symptoms at all. In addition, people with asthma, mold allergies or certain lung conditions may react more strongly.

However, symptoms alone do not prove that mold is the cause. Many health problems can cause similar signs. Therefore, anyone with new, ongoing or worsening symptoms should speak with a health care professional instead of trying to diagnose the cause from the building alone.

Common Mold Exposure Symptoms

According to Health Canada and the CDC, damp and moldy indoor spaces are linked with several breathing and allergy-related symptoms. These may include:

• Stuffy or runny nose
• Sneezing
• Red, itchy or watery eyes
• Eye, nose or throat irritation
• Coughing
• Wheezing
• Shortness of breath
• Skin irritation or rash
• Worsening asthma symptoms

These symptoms can also come from other causes. For that reason, do not use this list as a medical diagnosis.

Mold and Asthma

People with asthma may notice more coughing, wheezing, chest tightness or trouble breathing in some damp or moldy buildings. In addition, mold can trigger allergic reactions in people who already have a mold allergy.

If asthma symptoms become worse, follow your medical treatment plan and speak with your doctor. Also, seek urgent medical care for severe trouble breathing or other serious breathing symptoms.

Who May Be More Sensitive to Mold?

Some people may have a higher chance of health effects from dampness and mold. For example, Health Canada identifies children, older people and people with medical conditions such as asthma or severe allergies as groups that may be more sensitive.

People with very weak immune systems may also face a greater risk from certain fungal infections. Therefore, they should discuss possible mold exposure with their health care provider if they have concerns.

Does Black Mold Cause Different Symptoms?

The colour of mold does not tell you how someone will react to it. Black, green, white or other visible mold should all point you toward the same first step: find and fix the moisture problem.

Instead of trying to judge risk by colour alone, focus on the amount of mold, how long the area has stayed damp and whether anyone in the building has health concerns.

What Causes Indoor Mold and How to Spot It

Moisture Is the Main Cause

Mold needs moisture to grow. Common causes include leaking pipes, roof leaks, flooding, high indoor humidity, poor airflow and water that remains inside building materials.

The Health Canada guide to moisture and mould recommends fixing the moisture source and removing mold rather than trying to determine a safe indoor mold level.

Signs of Mold in a Home or Building

Visible spots are one warning sign, but mold can also grow in places that are harder to see. For example, watch for:

• Black, green, white or other coloured growth
• Musty or earthy smells
• Water stains on walls or ceilings
• Peeling paint or wallpaper
• Soft or swollen building materials
• Repeated condensation
• Past leaks or flooding
• Mold that keeps returning after cleaning

If mold keeps coming back, the moisture source may still be active. In that case, a property inspection or moisture check can help locate the problem.

Hidden Mold After Water Damage

Water can move behind drywall, below flooring and into ceiling spaces. As a result, mold may develop where it is difficult to see.

If you suspect a hidden plumbing problem, water leak detection can help identify damp areas and the likely source. Most importantly, fixing that water problem helps stop mold from returning.

Reducing Mold Health Risks and Fixing the Source

Control Moisture First

The best way to reduce mold symptoms and health risks in a damp building is to address the water or humidity problem. First, repair leaks. Next, dry wet materials. Then improve airflow where needed.

Health Canada also recommends keeping indoor humidity under control and dealing with water damage promptly. As a result, good moisture control makes it harder for new mold growth to develop.

Small Mold Areas vs. Larger Problems

Homeowners can often clean very small areas on suitable hard surfaces with basic cleaning methods. However, large areas, recurring growth, sewage-related damage or mold inside walls may need professional help.

GTA Restoration provides mold removal and remediation for properties where the problem requires containment, material removal, cleaning or moisture correction.

Do You Always Need Mold Air Testing?

No. Visible mold and a known moisture problem may already provide enough information to begin fixing the cause and planning cleanup. However, air testing can help in some cases when more information is needed.

Health Canada notes that mold levels can change from place to place and over time. Therefore, simply finding mold spores in an air sample does not automatically prove that a building has a harmful condition.

For more information, read our guide about mold inspection and testing for indoor air quality.

When to Speak With a Health Care Professional

If you have ongoing coughing, wheezing, shortness of breath, irritated eyes or other symptoms that concern you, speak with a health care professional. Also, tell them if symptoms seem worse in a damp building or improve when you leave it.

People with asthma, severe allergies, chronic lung disease or a weak immune system should take ongoing symptoms seriously. Meanwhile, a doctor can assess the medical side while a qualified restoration or indoor air professional checks the building.

Mold Symptoms Do Not Replace a Building Inspection

Health symptoms cannot tell you where mold is growing or what caused it. Likewise, a building inspection cannot diagnose a medical condition. Therefore, both questions need the right professional.

Ultimately, understanding mold symptoms and health risks means looking at both the person and the property. Address health concerns with a medical professional while also fixing leaks, dampness and visible mold inside the building.

If you have visible growth or a moisture problem, early action can help prevent the affected area from becoming larger. In addition, clear mold symptoms and health risks information should guide sensible action without creating unnecessary fear.

Concerned About Mold or Hidden Moisture?

GTA Restoration provides mold inspections, moisture checks, mold remediation and water damage restoration throughout Toronto and the GTA.

Visible mold, musty odour or recurring moisture? Find and correct the source before the problem spreads.

Call Us: 416-800-0000

Learn More

Everything You Need to Know About Biohazards Waste Contamination | What are Signs of Mold Exposure | How to Identify and Safely Remove Mold in Air Ducts | What Is Black Mold? Symptoms, Prevention, and Solutions | Water Damage & Mold Growth Precautions to take in winter months