Home » Mold 101: The Basics (With Layman’s Terms)

Mold 101: The Basics (With Layman’s Terms)

by BrianReeves
molds on the corner of the wall

What is Mold?

Mold (sometimes referred to as mildew) is a microorganism that has been classified as a fungus.  All fungi – whether mold, mushrooms, or yeast – share these three biological attributes:

Defined cell walls – Only organisms such as fungi, plants, bacteria, and algae have cell walls, while animals do not.  Therefore, mold is not an animal.


They reproduce via spores – In fact, the type of spore (similar to plant pollen) – the way it is produced (how it grows and is attached to the mold base), its form of reproduction (most are asexual while the rare spores are sexual), and what type of carrier it uses (think: pollination) to find a suitable habitat, such as animals, water, or air – is what determines the class of mold and sometimes, whether or not it is toxic or benign.  Although the maturing and release of the spores greatly resembles what takes place in plant pollination (using the air currents or passing animals as carriers), it is missing one key ingredient that every plant has.

They lack chlorophyll – Chlorophyll is used by plants to absorb sunlight and they use that energy to synthesise carbohydrates from carbon dioxide and water.  In other words, chlorophyll aids in photosynthesis.  Molds do not photosynthesize, and in fact, grow best in dark – sometimes pitch-black – habits, which means mold is not a plant.

Layman’s terms:  Well, it’s not an animal and it’s not a plant.  It’s a fungus…. and, it’s mold.  Mold is mold.  If you’re a fungus, you’re either mushrooms, yeast, or …mold.  That’s as simple and as basic as it gets.

What Makes Mold Grow?

The existence or growth of a mold depends on the conditions of their environment:

Temperature –  Mold thrives in warm temperatures, ranging anywhere from 40 F to 100 F.  Normal, indoor temperatures that most humans would find comfortable (67 F to 72 F) are also well-suited for mold growth.  It is rare for mold to grow below 40 F or to exist above 100 F, but there have been a few known cases.  As for whether or not a mold will die off below 40 F or above 100 F, the unfortunate truth is this:  except for a handful of molds, 99.99999% of all molds will simply lie dormant until growth conditions improve.  Once temperature reaches a more favorable level, it is guaranteed that the mold will continue to thrive.

Water Activity & pH Balance – Otherwise known as moisture, this is truly the cornerstone of fungi growth.  Many mold species can simply live off the humidity in the atmosphere, especially if it reaches a level of 70% or higher.  Most molds can live directly off the moisture contained within the dead organic material they have attached to (such as plants, decomposing food, wood, etc.).  Others need a readily available and frequent water source – this is where a leaky roof, toilet, bath-tub, inefficient refrigerator, or cracked pipe comes into play.  An interesting fact:  mold cannot grow in pure water, there must exist a good ¾ or greater balance of water/salt (pH Balance).

Lack of Ultraviolet & Synthetic Light – Since mold does not photosynthesize, it has no use for light.  Most molds and their growth are not directly affected by ultraviolet or otherwise synthetic lights.  That is, to say, that it is possible for molds to grow and thrive in an indirectly lighted environment.  However, growth may slow or stop completely for many molds if they are not based in a dark – or mostly dark (such as bathrooms when the light switch is mostly off) – area.  This is why molds grow rapidly in basements, walls, flooring, and food items stored in dark pantries or refrigerators that only light up when the door is opened.

Nutrients – Aside from temperature and moisture, mold cannot existence without nutrients.  Mold is a very specific type of microorganism that lives primarily on dead, organic materials, such as plants, papers, fabrics, wood, and decomposing foods and animals; but it might be surprising to know that some molds can metabolize nutrients from inorganic material as well, such as paints and adhesives.  Needless to say, the concern for mold should not end in the bathroom or kitchen.

Layman’s Terms:  Mold lives a rather sedentary, loitering life.  If mold were a person, he’d be the 40-year-old, divorced son in the basement of his elderly parents, playing video games in the dark, surrounded by empty pizza boxes and soda cans, a general musty stench about him, always wearing a damp-in-the-pits t-shirt.  Yeah, that’s mold, alright.  Remember:  mold enjoys warm, dark, and damp places.  Pizza doesn’t hurt either.

What is Toxic Mold?

A mold is considered toxic or poisonous if it has deadly effects on humans or other vertebrate animals (animals that have spinal columns, such as birds, reptiles, mammals, amphibians, and various fish).  The toxins or poisons are able to infiltrate the victim in three ways:

Ingestion – The primary route through which most toxic molds enter and begin affecting the victim is through ingestion.  Reproductive spores may land on food or the mold itself may grow on edible materials that the victim has chosen to eat.  Once inside the unfortunate victim’s mouth, the toxin – in the case of molds, it is known as a mycotoxin (the protein molecule produced when a toxin-capable mold metabolizes its nutrients) – is quickly and efficiently absorbed through the vertebrate’s mucous membranes (lining of the mouth) and later, deposited in the stomach where more damage is possible, especially in the case of mycotoxins that are less likely to succumb to digestive enzymes.  This enables the mycotoxins to travel the fastest and to the most vulnerable organs and susceptible tissues.

Inhalation – Simply put, a victim breathes in the mycotoxin and once the airborne spores reach the lungs, touch mucous membranes, or begin traveling through the pulmonary circulatory systems of the lungs, it can grow rapidly and many of the victim’s toxicity symptoms can begin occurring within hours of inhalation, depending on how much and how potent the mycotoxin is.

Contact – Probably the most uncommon infiltration occurs during the transferring of mold toxins via physical contact.  Although uncommon, this scenario should not be taken lightly.  Some mycotoxins can enter in through the skin, while others can lie dormant on the skin, hair, or clothing, until the victim touches their mouth, eyes, genitals, or fresh or open wounds – thus, giving the toxin a favorable condition of passage (mucous membranes, moisture, heat, etc.) and growth.  It is still possible for an “airborne” mycotoxin and an “ingestion-only” mycotoxin to reach their goal through physical contact.

Layman’s Terms:  Snakes.  There are regular snakes and venomous snakes; both bite.  Mold.  There are non-toxic molds and toxic molds; both wreak havoc on your health.  Point is, just as you should know your venomous snakes, you should also become aware of the toxic molds and how they can infiltrate your body.

What Symptoms are Produced by Toxic Mold?

Although there is some debate as to whether the most toxic mold is the black stachybotrys chartarum mold or one of the more rare white molds whose toxicity level has been equaled to that of a nut-allergy victim eating a bag of peanuts, most toxic molds in general will produce various types of symptoms in a victim, such as:

Mental symptoms – A victim of toxic mold may feel that their brain or thoughts are “foggy,” or they may feel confused.  They may suddenly exhibit a short attention span or have a difficulty concentrating.

Neurological symptoms – A victim may also experience delayed responses, slow reflexes, disorientation, dizziness, memory loss, memory issues, and an impaired learning ability.  Another good indication of toxic mold effect is the experience of hallucinations, numbness or tingling in one or more parts of the body, trembling, seizures, and uncontrolled shaking of the limbs or head.

Emotional symptoms– Toxic mold victims experience shock, anxiety, aggression, depression, and personality changes.

Respiratory symptoms – Many victims experience coughing, trouble breathing, lung infections, wheezing, shortness of breath, a swelling of the lungs (Pulmonary edema) or a bleeding in the lungs (Pulmonary hemorrhage), along with other more common and immediately noticeable respiratory effects, such as a bleeding, stuffy, runny, or itchy nose, bleeding gums, sore throat, or a burning sensation in the mouth.

Vision & Eye Issues – Victims also may complain of experiencing blurry vision, sore eyes, swelling or inflammation on or near the eyes.  They may have unexplainable red (bloodshot) or yellow (jaundice) eyes.  There may also be obvious damage to the eye.

Circulatory symptoms – Toxic mold can cause damage to the heart (such as inflammation).  It can also cause a tendency for bleeding – internal bleeding – (in all areas of the circulatory system and in the brain and other vital organs) and can also cause a victim to vomit blood.  A victim’s blood may lose the capacity to clot correctly or efficiently.  Probably the most overlooked toxic mold effect of circulation is low blood pressure.

Skin symptoms– Victims experience dermatitis (skin inflammation, rashes, blisters, general uncontrollable itchy feelings), jaundice (unhealthy yellowing of the skin), and sensations described as “crawling skin.”

Reproductive symptoms – Most victims are unaware that many of their reproductive issues stem from toxic mold, such as impotence, infertility, miscarriage, and problems in the development of the fetus itself.

Immune system symptoms – A good indicator that someone is a victim of toxic mold is the recurrence of infections.  A more serious result of toxic mold on the immune system is immunosuppression (when the immune system is not and cannot function properly).

Other Common symptons –  Most toxic mold symptoms in individual victims are overlooked or misdiagnosed (unless the same symptoms are found in multiple cases at the same time, such as what occurred after the 2011 Joplin, Missouri tornado).  Many of the more common and overlooked symptoms are as follows:  unexplained exhaustion, drowsiness, chronic fatigue, general weakness and aches or pains in various parts of the body (such as muscles, joints, chest, or abdomen), a general feeling of discomfort, unusual, chronic, and recurring headaches, as well as flu-like symptoms or a cold that “won’t go away.”

Layman’s Terms:  Wow.  Just.  Wow.  Stay away from mold, it causes so many symptoms that even your doctor could misdiagnose you and waste precious time that could be dedicated to saving your life.

Are All Molds Toxic?


The unfortunate truth is that, while not all molds are considered deathly “toxic,” all molds are potentially hazardous to humans and other vertebrate animals.  Whether it’s the mildew in the bath-tub, the strange discoloration in the linoleum, or the mold you casually scraped off your cheese, every single one of those molds – whether brown, white, gray, pink, black, green, or yellow in color – are all capable of causing the following:

Allergic Reactions (akin to hay fever)





…and even Asthma Attacks

In those who have weakened immune systems, nutrition deficiencies, and/or an already existing illness, infiltration from even the most seemingly benign mold can eventually cause severe lung infections.

Layman’s Terms:  Do I need to mention those snakes again?  Remember:  All molds are hazardous, just as all snakes bite.

Which Molds Should I Worry About Most?

When encountering any mold in a living space for humans or animals, it isn’t necessarily to discover which type of mold it is.  All molds have the potential to cause damage to the health of a human or animal, whether they are classified as poisonous or considered common.

Layman’s Terms:  Go ahead, harbor prejudice.  This is the only scenario where it’s healthy and safe to do so.  Hate mold with a passion.  The solution?  Whatever type it is – toxic or common –  get rid of it.

The Solution to Any Mold?

Be proactive.  Don’t give it an environment it can live in.  Start by getting rid of the moisture or water in the area.  Leaky pipes?  Replace them.  Flooded basement?  Drain it, get a dehumidifier, dry it up, block the leaks.  Leaking roof?  Fix it.  (No matter what the issue is, always keep in mind that no amount of money will replace your health and the lives of your family, your pets, or your renters.)  Keep the area at a steady, non-fluctuating temperature (or even at a cooler degree if you’re able).  Bring in natural light (just in case you’re dealing with a mold that cannot grow well in ultraviolet light).  Lastly, keep all areas as clean as possible.  Mold needs nutrients.  Starve it.  Finish wood flooring with a protective coat.  Use mold-resistant paint.  Sweep up those crumbs.  Clean out that refrigerator.  Complete monthly mold inspections yourself, check all dark, damp, and warm areas of your house, workplace, and vehicle.  If you do discover mold, please check out safe, removal solutions at Moldblogger.com and feel free to ask questions.

Layman’s Terms:  Don’t give mold a chance to grow in the first place.  Remember these three main steps to avoiding mold: dry, cool, clean.  If you already suffer from mold, you’ve come to the right place.  MoldBlogger will help you fight mold and win!

Beankeeper is a mother of two, a business owner, and a freelance writer.  You may find her other works at The Wife’s Life, a blog devoted to those who still believe in wholesome living, dedicated parenting, and faith-filled marriages.  She is also a content-writer for the folks at Lots of Motts, a webstore making coin collectors’ dreams come true since 2011.


photo credit: PhotoDu.de / CreativeDomainPhotography.com via photopin cc

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Tricia June 27, 2014 - 8:37 am

I have no mold in my house but it is growing in my clothes. It is a grey/white mold that I see on my black pants and darker clothes. I have 3 closets, 1 where I keep my seasonal clothes and it grows in all three. My husband’s clothes are in the same closet in the bedroom and he has NO MOLD in his clothes.There is no mold in any of the closets. I’ve soaked all my clothes in vinegar and washed them in an anti mold solution but it keeps growing back after a couple of weeks. I am Type 1 diabetic so naturally have higher bloodsugars. Could this be feeding the mildew in my body that is showing up on my clothes. I had a test done that shows I have mildew internally and treated it with an antifungal. I am at my wits end as how to get it out of my clothes. This has been going on for several years.

Beankeeper June 27, 2014 - 9:37 am

Tricia – Here is another great link for herbal and essential oil solutions: http://aromatherapy4u.wordpress.com/got-mold-essential-oils-kill-mold/

BrianReeves June 27, 2014 - 9:38 am

Have you tried washing the clothing with tea tree oil? https://moldblogger.com/cleaning-mold-with-tea-tree-oil/

Tricia June 28, 2014 - 2:22 pm

Thank you for the quick and informational reply. I will spray an essential (and edible) oil called Sunbreeze that has eucalyptus, cinnamon oil, camphor, menthol and mint in the closet and on the clothes and observe. The Sunrider Laundry soap that I use contains tea tree oil along with other herbal extracts. I will try treating the internal issue with frequency. Thank you again.

Annie September 7, 2014 - 1:59 pm

Interesting! I think the real answer lies somewhere in the questions: why don’t his clothes grow mold? What is different? If it is the diabetes, wouldn’t the sugar be washed out in clean clothes?
Maybe instead of spraying the clothes,which also increases the humidity & moisture, you might try placing a dessicant in the closets, something like cedar chips, salt or other material? I wouldn’t use moth balls, too toxic, but that’s the same idea.

Tricia September 11, 2014 - 7:32 am

Thanks Annie, I’ll give it a try

Joe November 30, 2017 - 1:06 am

Great article on mold. Mold growth can happen just about anywhere. It’s good to keep people informed of the dangers and what to look out for when dealing with such a nuisance.


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