Most people breathe fungal spores daily without getting sick

Fungi make people sick when they invade and survive in otherwise healthy human tissue

We breathe in airborne spores frequently, but they often don't make us sick. This video details how certain concerning fungal changes can occur and discusses the role of mycologists—scientists who study fungi—in helping to improve human health.

Cryptococcus neoformans, a growing threat, causes infections in the brain and lungs

This inhalable, microscopic pathogen is found worldwide. It rarely causes illness, but it can take root in those with compromised immune systems, including people with advanced HIV/AIDS. Symptoms of cryptococcal infection—such as a stiff neck, vomiting, and confusion—can begin weeks or months after breathing in spores, though sometimes symptoms won’t appear for years. There are no known cases of transmission between people or between people and animals.

19 fungal pathogens are of key concern to world health officials

In 2022, this global health body issued its first-ever list of top fungal threats to human health. It said fungal threats are spreading and occurring more frequently. The WHO’s list included 19 fungal pathogens to watch, and said that the most dangerous ones to public health are Cryptococcus neoformans, Aspergillus fumigatus, Candida albicans, and Candida auris. There are only a handful of classes of medication currently available to combat fungal pathogens, with few others in the pipeline even though antimicrobial resistance is growing.

Fungal diseases cost the US around $19B annually.

Most fungal pathogens can't survive the heat of our bodies.

Black mold isn’t more worrisome than other colors of mold

Black mold typically refers to Stachybotrys chartarum, a mold that commonly appears in damp or water-damaged areas of the home. Black mold—and other molds—won’t typically make otherwise healthy people ill, and all molds should be treated the same with respect to health risks and removal. If you have mold allergies, mold can cause an allergic response, and it can trigger asthma attacks for people with asthma. If you have a compromised immune system, then black mold exposure can also cause a fungal infection in your airways or elsewhere in the body.

Mapping the spread of a dangerous fungus growing in US healthcare facilities

Explore the data showing how the fungus C. auris has spread in the US, with more than 10,000 reported cases since 2016. Recommended steps to prevent infections and limit their spread have been successful in some areas, but infection control remains complicated because the fungus is often now multidrug-resistant.

Particles found in Martian air pose significant risks to human lungs

Ultrafine dust, just 3 micrometers wide, is small enough to bypass lung defenses and enter the bloodstream, where its highly reactive chemicals can cause thyroid disease. Silica in the dust can also cause silicosis, a chronic and incurable lung disease.

Candida auris spreads easily in healthcare facilities and causes high death rates

This fungus has spread rapidly in healthcare settings since the first US case was reported in 2016, and it has grown increasingly resistant to echinocandins, the antifungal medicine most commonly used to treat it. Often, it’s resistant to multiple antifungal drugs, contributing to its high death toll. It can most readily infect those with invasive medical devices like intravenous catheters and those with frequent or long-duration stays in healthcare facilities.

Mycotoxins are toxic compounds produced by fungi—some show up in food

About a quarter of the world’s agricultural products are contaminated with mycotoxins. Some of these compounds can cause serious health problems, including cancer, so the US government has set up monitoring programs to detect them in our food and in animal feed. Humans can become ill if they eat contaminated food, but also if they ingest products from animals that had previously consumed these toxic compounds, such as milk from a cow that ate contaminated corn.

Flu spreads through droplets in the air and on surfaces

Influenza passes mainly through tiny droplets released when sick people cough, sneeze or talk. The virus can also survive briefly on surfaces, allowing it to spread when others touch contaminated objects.

Fungi can cause disease, but they’re also our planet’s key decomposers

Fungi are their own taxonomic kingdom separate from flora and fauna, acting as the key decomposers and nutrient recyclers for our planet. Watch this video to understand the diverse types of fungi and the stages of the fungal life cycle. This video illustrates how fungi species may spread, eat nematode worms, damage nearby plants, and much more.

Some dementia cases may be linked to treatable microorganism infections in the brain.

Natural toxins produced on plants or consumed by animals may cause food poisoning

When humans eat plants with certain natural toxins on them—including a family of toxins called aflatoxins that fungi produce on crops like peanuts and corn— they can become ill with food poisoning. Toxins can still harm humans even if animals or plants appear fine to the human eye. The World Health Organization advises that we should throw away moldy or discolored foods, refrain from eating wild plants or mushrooms that aren’t definitively nonpoisonous, and remember that just because something is “natural” it’s not always safe to eat.

Amish kids have far fewer allergies than the general population

Only about 7% of Amish children in a northern Indiana community have tested positive for common allergens in routine skin prick tests, whereas half of the general US population tests positive for them. Asthma is also extremely uncommon among the Amish, even when compared with other farming communities. Researchers are interested in exploring if approaches like exposing kids across the general population to Amish farm dust might stave off some allergies.

What is asbestos, actually?

Asbestos can hurt you, but not many people understand how or why. Asbestos is actually a stone, once frequently employed as a construction material due to its strength, softness, fire-resistance, and biodegradability. However, when working on old homes or furniture, it may be released into the air, and extended exposure to its particles may cause lung cancer. Its use in new construction has been banned, but it remains a hazard. Learn more here.

Research suggests the cleanliness of the ISS may make astronauts unhealthy

The International Space Station's sterile conditions deprive astronauts of the opportunity to strengthen their immune systems through microbial exposure. To address this problem, future missions may use probiotic-based cleaners and foster diverse microbes in space habitats.

One in six Americans contracts food poisoning each year.

Cutting mold off your food does not make it safe to eat

Mold is a type of fungus, but not all fungi are molds. This video explains the value of mold, mold anatomy, health concerns around encountering and eating mold, and why mold is found all around us.

Mold growth in space raises the hypothesis of life being brought to Earth

Panspermia suggests that life could be carried throughout the cosmos by asteroids, comets, and other objects, but it requires organisms that can withstand the extreme cold of space travel, stellar radiation, lack of water, and intense heat of planetary impacts. The discovery of mold on the International Space Station and experiments showing it can withstand radiation in outer space-like conditions increase the plausibility of the hypothesis.

Billion-year-old Arctic fossils suggest Earth had fungi far earlier than previously thought

Named Ourasphaira giraldae, this new species of fungus, reported in 2019, was found in the Grassy Bay Formation in the Canadian Arctic. It pushed the fossil record of fungi back by about half a billion years since the oldest previously recognized fungi fossils came from the Rhynie chert, a Scottish site that dates back roughly 400 million years. This fungal discovery also suggests that fungi may have occurred on land much earlier than plants, raising questions about what ancient fungi used for nourishment.

Unlike food allergens, encountering inhaled allergens—like pollen—rarely causes life-threatening illness.

Hand, foot, and mouth disease spreads easily—including via fomites

The common ailment spreads through respiratory droplets, touching infected secretions like poop, but also by touching virus-laden fomites, which are contaminated objects such as doorknobs or toys.

Watch an expert's take on the rare disease hantavirus—and why it's not of great concern to the general population

This rare zoonotic disease, transmitted to humans primarily through infected rodent droppings, urine, or saliva, is rarely spread between people. The disease was of particular concern in spring 2026, when an outbreak occurred on a 150-person cruise ship, prompting a flurry of action, including contact tracing for passengers in their home countries. The disease can be fatal. But early care—primarily oxygen support—can help patients survive.

We can get food poisoning from spending time in swimming pools, lakes, rivers, and ponds

Some of the same pathogens that may sicken us in food or water may also sicken us in recreational swimming environments. Bacteria can rub off of people’s (or animal’s) bodies or contaminate the water through a diarrheal episode. Washing your hands for at least 20 seconds before eating food if you are at the beach, pool, or other similar environments and being sure not to swallow the water are ways to help keep safe.

Broken or neglected air conditioners are risky for respiratory health

A well-maintained air conditioner can typically keep out unwanted pathogens, but units that are dusty or water-logged can foster germs and cause harm. AC units also remove moisture from the air, potentially causing mucus membranes to dry out and become vulnerable to infection.

On average, people smell worse if they're sick

For a small 2014 research study, a panel was tasked with sniffing the smelly t-shirts of people who had been injected with a compound known to activate the immune system and those of controls without the shot. It found that those who were acting as if unwell (due to the injection) generally smelled worse. Subsequent work found that those who sniffed unpleasant odors had a mild immune response of their own—perhaps to protect them from disease. (Some users may experience a paywall.)

Tornadoes can cause significant air pollution and diminish air quality

Asbestos, a hazardous material that can cause lung cancer, is commonly found in buildings constructed before 1980. Tornadoes that damage such buildings can release asbestos into the air, along with other toxic pollutants and dust as materials are lifted. Individuals, particularly those with asthma or other chronic lung diseases, are encouraged to wear masks after a tornado.

Influenza infects up to a billion people worldwide each year

The World Health Organization estimates that seasonal influenza causes about 1B cases annually, including 3 to 5M severe illnesses and between 290,000 to 650,000 deaths.

Inhalers dilate airways and reduce inflammation

People with asthma suffer from constricted airways in their lungs, whether from muscle pressure, mucus buildup, or inflammation. Inhalers help people breathe medicine directly into their lungs to immediately relieve these symptoms.

Candida albicans is a natural body-dwelling yeast, but it can cause yeast infections

This fungus is naturally occurring on the body, but C. albicans can become a problem when the natural balance of bacteria on the body is off-kilter, allowing this yeast to spread. It can cause anything from diaper rash to a yeast infection in the throat or vagina. It’s typically treated with doctor-prescribed antifungal medications.

Cordyceps: the fungi that turn ants into zombies

The hit show (and video game) "Last of Us" was inspired partly by real-life species of fungi that have been known to turn ants into zombies. Spores of the Cordyceps fungi are capable of penetrating the exoskeletons of arthropods, after which they break into enzymes and proliferate within the body. The fungal cells then hack the ant's nervous system and trigger compulsive climbing.

A 101 on the 'Death Cap,' the world's deadliest mushroom

The Death Cap, also known as amanita phalloides, is the most fatal mushroom on the planet, responsible for roughly 90% of the world's mushroom deaths per year. Ingestion of the mushroom wreaks havoc on the liver and kidneys, frequently leading to...

The ‘humongous fungus’ may be the largest organism on Earth at more than 2,300 acres

Discovered in 1988, when it was only covering 400 acres, this massive colony of Armillaria ostoyae, based in Oregon, has taken hold among the tree roots of the Malheur National Forest. It consists of a vast network of unique long black filaments of fungal tissue called rhizomorphs that grow under the soil and infect tree roots, nourishing the fungus but killing the trees. Researchers believe this fungal growth dates back more than 8,000 years and currently weighs approximately 35,000 tons.

Gut microbiome rewrites may help reduce allergies

Researchers are investigating different strategies to determine if one day they could give people a combination of gut microbes to set them up for fewer allergies. In animal research, scientists have already prevented severe allergic responses in allergy-prone mice—supplying them with gut microbes from healthy, non-allergic human babies.

The 9/11 plane crashes, which resulted in the collapse of the Twin Towers, created toxic dust that included materials including asbestos, silica, metals, concrete, and glass.

There are up to 100 trillion microbes in the gut, and maintaining the relative balance in this ecosystem is important for our health.

Adults usually have some immunity to HFM Disease—but can still spread it

In 2025, certain eastern states including Virginia and West Virginia reported a sizable uptick in their HFMD cases, particularly in their schools and daycare centers, though the reason for the larger outbreaks remains unknown. When adults or teens get the disease, their symptoms are usually mild or even asymptomatic. Still, they may pass the disease between people, too. (Some users may encounter a paywall.)

Microplastics have been identified across human body systems, with research finding they are most commonly ingested through inhalation, drinking water, and diet before crossing barriers into organs.

Drug-resistant staph infection is one of the deadliest superbugs, killing more than 120,000 people globally each year.

The resurgence of Black lung disease in coal miners

Black lung disease is a preventable condition long associated with coal miners who regularly breathe in toxic coal dust. Simple workplace safety procedures make the disease entirely preventable, but cases are rising. Due to lax enforcement of rules, miners in Central Appalachia are increasingly diagnosed with cases stemming from silica dust inhalation.

Approximately 70% of all polio infections in children are asymptomatic

Most polio infections are asymptomatic or appear with only flu-like symptoms. Infected individuals can still shed the virus in their stool and mucus for days or weeks

Farts are tiny status reports from our gut microbiome, with American adults typically passing gas more than 30 times daily.

Polio commonly spreads when virus-laden feces gets into our mouths

This highly infectious disease is transmitted from one person to another, mainly when we eat virus-laden poop particles. Less frequently, contaminated food or water can transmit the virus, or people can be infected via respiratory droplets (from coughing or sneezing).

Roughly 15 of every 1,000 people in the US have smell disorders

Anosmia is a lack of a sense of smell. It can be present at birth, related to diseases including Parkinson's, Alzheimer's, and COVID-19, or have unknown causes.

Legionnaires' disease is a serious lung infection caused by Legionella bacteria, and it's often contracted from inhaling contaminated mist or water.

Less than 1% of Americans are allergic to penicillin, though about 10% of Americans believe they have this allergy.

Seasonal allergies don't always show up in childhood

The human immune system may become sensitized to pollen and develop an allergic reaction to it after prolonged exposure. Other triggers for new seasonal allergies may include exposure to new environments and changing climate conditions that affect allergy season length and conditions for various pollens.

The science of food allergies

Why do certain substances trigger an immune response while others don't? Listen to researchers explain the science in this five-minute video. Food allergies affect around 8% of children and 2% of adults in the US, and—unlike sensitivity or intolerance—they involve the immune system mistaking certain harmless proteins in foods as dangerous invaders, triggering a rapid and sometimes severe defense response.

Adults are developing food allergies that they didn’t have as children

Research published in 2019 found that almost half of 40,000 surveyed adults with food allergies developed a new food allergy as adults, underscoring that our immune systems may newly misclassify substances later in life.