Los Angeles County · Mold and health
Mold and Your Health: What the CDC, EPA and WHO Say
According to the CDC, damp and moldy homes may cause a range of health effects, or none at all. The most common are allergy-type symptoms: stuffy nose, wheezing, and red or itchy eyes or skin. People with asthma, allergies, weak immune systems or lung disease can react more strongly. Talk to your doctor about symptoms, and fix the moisture.
- SourcesCDC, EPA, CDPH, WHO
- Our roleBuildings, not diagnosis
- CoverageAll of Los Angeles County
- Emergency24/7 response
- Call(213) 659-0672
The basics
Can mold in your home affect your health?
It can, but not in the same way for everyone. The CDC says exposure to damp and moldy environments may cause a variety of health effects, or none at all. Some people are sensitive to mold and notice symptoms quickly. Others live with the same conditions and notice nothing.
The EPA explains why. Molds release allergens (substances that can cause allergic reactions), irritants, and in some cases mycotoxins, chemicals that certain molds can produce. Mold can irritate the eyes, skin, nose, throat and lungs of people with and without mold allergies.
The World Health Organization (WHO) reviewed the research in its 2009 guidelines on dampness and mould. It found that people who live or work in damp or moldy buildings are at higher risk of respiratory symptoms, respiratory infections and worsening asthma. The common thread is dampness, not one particular mold.
What does the California Department of Public Health say?
The California Department of Public Health (CDPH) takes a simple position: water damage, dampness, visible mold or a moldy odor indoors should be treated as unhealthy. CDPH recommends against using measurements of mold in the air to decide how big the health risk is. Its advice is to find and fix the moisture problem and clean up the mold.
LA County Public Health takes a similar line and says testing isn’t needed to understand health risk. If you can see or smell mold, that alone is a reason to deal with it.
Symptoms
What are common mold exposure symptoms?
The symptoms the CDC and EPA describe look a lot like hay fever or a cold. That’s part of why only a doctor can sort out the cause. Pollen, dust mites, pets, smoke and viruses can produce the same signs.
- Nose and throat: stuffy or runny nose, sneezing, throat irritation.
- Chest: coughing or wheezing.
- Eyes: red, itchy or watery eyes.
- Skin: itching or a rash.
- Asthma: in people who have asthma and are allergic to mold, the EPA says mold can trigger asthma attacks.
The EPA notes that allergic reactions to mold can happen right away or be delayed. A pattern worth mentioning to your doctor is symptoms that are worse at home and ease when you’re away for a few days.
What does the research link to damp, moldy homes?
The CDC summarizes a 2004 Institute of Medicine review. It found enough evidence to link indoor mold or dampness with the following, and less certain evidence for some other effects.
| Health effect | Who | Source |
|---|---|---|
| Upper respiratory symptoms (nose and throat) | Otherwise healthy people | Institute of Medicine 2004, via CDC |
| Cough and wheeze | Otherwise healthy people | Institute of Medicine 2004, via CDC |
| Asthma symptoms | People with asthma | Institute of Medicine 2004, via CDC |
| Hypersensitivity pneumonitis, a lung inflammation | People who are susceptible to it | Institute of Medicine 2004, via CDC |
| Respiratory infections and worsening asthma | Occupants of damp buildings | WHO 2009 |
| Lung infections from mold | People with weakened immune systems or chronic lung disease | CDC |
A summary of agency statements, not a diagnostic list. Only a doctor can say whether mold plays a role in your health.
What’s missing from that list matters too. You’ll find claims online that household mold causes memory loss, chronic fatigue or other serious illness. The CDC says reports of rare conditions tied to so-called toxic molds are very few, and a cause-and-effect link hasn’t been proven. We cover this in detail on our black mold exposure facts vs myths page.
Higher risk
Who is more likely to be affected by mold?
The CDC names a few groups who may react more strongly or face more serious effects. If someone in your home fits one of these, it’s worth acting sooner on moisture and mold and keeping their doctor in the loop.
Allergies and asthma
People with mold allergies or asthma may have more intense reactions. Kids with asthma are a common worry in LA apartments. See mold, asthma and children.
Weakened immune systems
The CDC says people with weakened immune systems, for example from cancer treatment or an organ transplant, may get infections from mold. Their care team should know about mold at home.
Chronic lung disease
People with long-term lung conditions can also be more vulnerable, according to the CDC. They shouldn’t do mold cleanup themselves.
What about mold-sensitive households and CIRS?
Some people describe ongoing symptoms they connect to water-damaged buildings, and some doctors use the term CIRS (chronic inflammatory response syndrome). CIRS is a term used by patient communities and some practitioners, and it isn’t a settled diagnosis in the CDC, EPA, CDPH or WHO guidance we cite. We respect the concern and don’t take sides on the medicine.
What we can do is the building side: thorough moisture work, careful containment and strict clearance. Our page on testing and clearance for mold-sensitive households explains how that works, and ERMI and HERTSMI-2 dust testing covers the tests these households often ask about.
Next steps
What should you do if you think mold is affecting your health?
Handle the health side and the building side separately. Your doctor looks after you; a mold inspection looks after the home. Neither one can do the other’s job.
- Talk to your doctor. Describe your symptoms, when they started, and whether they change at home. Mention any visible mold, musty smell or past leaks.
- Find the moisture. Mold needs water. Look under sinks, around windows, in closets on outside walls, and anywhere that leaked in the last storm.
- Clean small areas safely, or get help. The EPA says areas under about 10 square feet can usually be handled yourself. People with asthma, allergies or weak immune systems should let someone else do it.
- Bring in an inspector for hidden or larger problems. A good inspection finds the water source first. Testing is useful for hidden mold, documentation or clearance, not for diagnosing you.
- Renters: report it. In the City of LA, LAHD inspects for free at (866) 557-7368. Elsewhere, check who to call in your city or our LA renter mold hub.
Does mold testing tell you if mold is making you sick?
No. A mold test measures a building, not a person. Air samples compare spores indoors with an outdoor control sample, and dust tests estimate which molds have settled over time. Neither can show what caused a symptom, and the EPA says there are no federal limits for mold or spores to compare against.
Testing still has honest uses: confirming hidden mold behind a wall, documenting a problem for a landlord, or checking that cleanup worked. Our guide to mold air quality testing explains what a spore count can and can’t tell you.
| Service | Typical LA range |
|---|---|
| Visual inspection with moisture mapping | $250–$500 |
| Inspection with 2–3 air samples plus an outdoor control | $400–$800 |
| Each additional air or surface sample | $75–$150 |
Typical industry ranges for the Los Angeles area. Your written quote depends on the size, access and materials involved.
What about mycotoxin tests, detox and supplements?
We don’t sell, recommend or interpret any test of the body, such as urine or blood tests for mycotoxins, and we don’t offer detox programs or supplements. Those are medical questions. If you’re considering one, ask your doctor what the result would mean and whether it would change your care.
At home
How do you reduce mold exposure at home?
Every agency we cite says the same thing: control moisture. The EPA advises drying water-damaged materials within 24 to 48 hours and keeping indoor humidity below 60 percent, ideally between 30 and 50 percent.
- Fix leaks first. Cleaning without fixing the water source means the mold comes back.
- Vent moisture out. Run the bathroom fan during and after showers and use the kitchen hood. Many older LA apartments have no bath fan, so crack a window.
- Watch the coast and the storms. Marine layer humidity near the beach and winter storms are LA’s two big mold drivers. Check closets on outside walls and window frames.
- Protect yourself during cleanup. The CDC suggests an N-95 respirator, gloves and goggles, and never mixing bleach with ammonia.
Questions
Mold and health questions we hear most
What are the symptoms of mold exposure?
The CDC and EPA describe allergy-type symptoms: stuffy or runny nose, sneezing, cough, wheezing, red or itchy eyes, and skin irritation. People with asthma may have asthma attacks. Many other things cause the same symptoms, so talk to your doctor.
What are black mold exposure symptoms?
According to the CDC, the risks from molds that can produce mycotoxins, including Stachybotrys, should be treated the same as other common molds. The symptoms described are the same allergy-type and respiratory symptoms. Any mold indoors should be removed, whatever its color.
How do I know if mold is making me sick?
Only a doctor can help answer that. A home inspection can show whether there’s mold and moisture in the building, but no test of a home can prove what caused your symptoms. Tell your doctor if symptoms improve when you’re away from home.
Is a mold allergy the same as mold exposure?
Not exactly. Exposure means breathing in or touching mold. An allergy is one way some people’s bodies react to it. The EPA says mold can also irritate people who aren’t allergic. A doctor can tell you whether you have a mold allergy.
Is it safe to stay in a home with mold?
It depends on how much mold there is and who lives there. Small areas are common and fixable. Large growth, or a household member with asthma, a weak immune system or lung disease, is a reason to act quickly and ask your doctor.
Should I test my home before seeing a doctor?
No. See your doctor about symptoms first. The CDPH and LA County Public Health both say testing isn’t needed to judge health risk. If you can see or smell mold, fix the moisture and clean it up.
Is there a safe level of mold in a home?
No official one. The EPA says there are no federal limits for mold or spores, the WHO did not set numeric limits, and California never adopted exposure limits. The agencies focus on fixing dampness instead.
Do you give medical advice?
No. We’re mold professionals, not medical providers. We find moisture, assess mold and remove it. Questions about symptoms, tests of the body or treatment belong with your doctor.
Sources
- Centers for Disease Control and Prevention (CDC), mold and health: cdc.gov/mold
- U.S. Environmental Protection Agency (EPA), mold resources: epa.gov/mold
- California Department of Public Health (CDPH), statement on building dampness, mold and health
- World Health Organization (WHO), Guidelines for Indoor Air Quality: Dampness and Mould (2009)
- Institute of Medicine, Damp Indoor Spaces and Health (2004), as summarized by the CDC
- LA County Department of Public Health, Environmental Health: publichealth.lacounty.gov
Last updated November 2026. This page is general information from public health agencies, not medical advice. We’re mold professionals, not medical providers; talk to your doctor about symptoms. Prices are typical Los Angeles ranges, not a quote.
Worried about mold in your home?
Call (213) 659-0672, 24/7 across Los Angeles County. We’ll find the moisture source, explain what we see in plain language, and give you a written quote before any work starts.