Lengthy incubation periods are why it’s tough to link foodborne illness to specific foods

See the incubation periods for certain food poisoning-causing organisms

Read this chart that lists common food sources of different foodborne illness-causing pathogens and typical times between exposure and symptom onset.

Food poisoning can sometimes cause serious long-term health issues

Although foodborne illness can be relatively mild and cause short-term discomfort, more rarely it can also cause long-term severe health consequences, depending on your individual risk factors, the severity of your sickness, and the care you receive. Kidney failure is one serious complication associated with certain types of food poisoning. Meningitis, hepatitis, arthritis, and pancreatitis are also rare and serious foodborne illness complications. If a pregnant person gets food poisoning, it can cause health issues for the fetus.

Restaurants are where most of us contract food poisoning in the US

From 2014 to 2022, most reported foodborne illness cases occurred at restaurants. Between 2020 and 2022—when COVID-19 also likely influenced restaurant eating habits and tracking—there were only 238 foodborne illness outbreaks linked to restaurants, down from 714 the prior two years. Still, restaurants were behind most reported outbreak cases. (Some readers may experience a paywall.)

See why food poisoning makes you feel nauseous

Scroll through these illustrations to learn what’s happening behind the scenes with bacterial foodborne illnesses, including why we sometimes vomit and how the body reacts to toxins secreted by bacteria.

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.

Just because leftovers look and smell okay doesn’t mean they’re safe to eat

Despite what the sniff test is telling you, older leftovers should probably be trashed. Pathogens that cause illness don’t usually affect the taste, smell, or appearance of food (though if they look bad, you should chuck them as well). Scientists recommend tossing leftovers within a few days even if they appear to be fine.

Leprosy bacteria replicate extremely slowly—only once every two weeks

Mycobacterium leprae has a long incubation period and a very slow replication rate, taking roughly 12 to 14 days to make a copy of itself and divide. In contrast, bacteria like E. coli can replicate in about 20 minutes in ideal conditions. Someone can be infected for years without experiencing any symptoms. This also makes the disease difficult to treat. This video describes the knowns—and unknowns—about this infectious bacterium.

Pooping or puking out pathogens is sometimes recommended with food poisoning

Sometimes stopping food poisoning-linked diarrhea with over-the-counter medications is a bad idea because it may prolong illness. Doctors can advise you if your diarrhea or vomiting is severe about what medications to take and when, but generally doctors recommend trying to stay hydrated during a bout of food poisoning and letting the body naturally remove pathogens from the body via vomiting or diarrhea, as needed.

Neural replays in mice help explain food aversions

Princeton University scientists published research in 2025 analyzing how mice learn to associate certain foods or flavors with feeling ill—even when there’s a time gap between eating something and feeling sick. The work, performed with grape Kool-Aid and injections of a substance that made mice sick, traced the literal “gut reaction” of how gut distress signals are linked to neural replays of what the mouse ate.

Ticks must typically be attached to a person for more than 24 hours to transmit Lyme

Infected blacklegged ticks must typically be attached to a person for more than 24 hours—and often closer to 36—to transmit Lyme. That period is enough time for the bacteria that causes Lyme to migrate from the tick's gut into the person's bloodstream while it's latched on through its bite. (There are rare documented cases of transmission under 24 hours.) Rapid removal of the tick is key to disease prevention.

HFMD can survive on surfaces for days at a time

That's why the virus can be transmitted via fomites—surfaces that have virus on them like doorknobs, kids toys, etc. These viruses are resilient—they are often even resistant to freezing (and are frequently stored at freezing temperatures in lab settings).

In 1892, two scientists purposefully infected themselves with cholera bacteria

When they became ill—one with mild diarrhea and the other with severe cholera—researchers pointed to that as proof that the pathogen caused the disease.

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.

Since 1600, the longest stretch without an outbreak that killed 10,000 was four years

We think of pandemics as unlikely events, but disease outbreaks are surprisingly common. Over the past 400 years, the longest stretch without an outbreak that killed at least 10,000 people was just four years. The next pandemic can't be precisely known, so experts and policymakers focus on preparation.

Zoonotic diseases: Pathogens that jump from animals to humans

Such diseases may be caused by a variety of pathogens—viruses, bacteria, fungi, or parasites—and can originate in creatures ranging from ticks and mosquitoes to pigs and bats. Because they develop in animals and are often new to human immune systems, zoonotic diseases have severe consequences for public health.

Cantaloupe’s textured skin boosts the risk of food poisoning

Food safety expert Darin Wetwiler says he prefers to stay clear of this fruit altogether since it’s so hard to keep the textured skin pathogen-free. He advises trying to avoid pre-cut cantaloupe in particular, since consumers won’t know when the fruit was sliced and pathogens on the outside could have been spread to the part we consume during slicing and multiplied.

Lactose intolerance is not the same as a dairy allergy

Lactose intolerance can develop in adulthood and can be influenced by genetic factors, culture, and dietary practices. Times of famine may have favored those who could digest dairy, naturally selecting them more, resulting in lactase persistence.

Long-haul COVID: What doctors want patients to know

Long COVID continues to be a medical mystery, but some parts of the puzzle are falling into place. Learn more from intensivist Devang Sanghavi, MD.

Symptoms of extreme radiation exposure may take hours to manifest

Large doses of ionizing radiation can damage the body within minutes, particularly in the bone marrow and inner layer of the digestive tract. Victims may briefly seem fine before rapidly deteriorating as immune failure, infection and organ collapse set in.

Food allergies were first documented more than 4,000 years ago

Although food allergies are on the rise in modern times, they have been documented in written records for thousands of years. More than 3,000 years ago, Chinese emperors advised patients to avoid certain foods, and Hippocrates noted in his work that food could cause serious harm to certain individuals, and even lead to death.

How the microbiome affects your health

The gut microbiome is so influential to overall human health that some researchers consider it a separate organ. Its conditions, influenced by environmental and lifestyle factors such as medication and exercise, contribute to immunity, metabolism, inflammation, medical treatment efficacy, brain development and function, and the development of disorders and diseases, including asthma, depression, inflammatory bowel disease, and Alzheimer's.

It can take 10 to 15 years and more than $1B to develop a new antibiotic.

Why don't we just develop new antibiotics? In part, it's a complex scientific challenge, but market incentives also play a significant role. It can be time consuming, expensive, and most notably, we should use as little as possible to avoid driving further antibiotic resistance.

Interest in intermittent fasting outpaces the science

The public interest in fasting diets has outpaced the science behind related health claims. This article details how the science of fasting diets is mainly exploratory and focused on longevity and disease prevention. Current findings suggest fasting kick-starts regenerative processes in the body, decreases inflammation, and improves health outcomes overall. However, much of this research focuses on the short-term impact of fasting.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Fevers are an immune response to create hurdles for pathogens

Substances called pyrogens prompt the brain to raise the body temperature to levels where bacteria and viruses struggle to survive. The higher temps also support immune cells fighting off the invaders.

Due date is calculated from the first day of the last menstrual period—not when sex occurred

The standard counting system considers a woman pregnant from the first day of her last menstrual period, which means someone may technically—for the purposes of measurement—have become pregnant even before she had sex. This standard starting point is used because it reliably marks when the body began preparing for pregnancy—even though it's typically two weeks before conception. On average, most women are pregnant for 280 days from the last menstrual period.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

The 2026 Ebola outbreak is hampered by a lack of vaccine against the species of the virus, heightening the need for rapid tests to aid in disease control.

This real-time tracking of the hantavirus cruise ship outbreak in May 2026 offers a unique glimpse into the global reach of the outbreak and whether the virus sickened passengers and their communities around the world.

Urushiol, the oily toxin in poison ivy, can remain allergenic on clothing for years.

About 12.5% of US adults experience a phobia in their lifetime, a diagnosis that hinges on the intense fear interfering with daily life and persisting for at least six months.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

Tattoos remain visible on your skin thanks to immune cells called macrophages

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

Telehealth demand for GLP-1s for weight loss is booming as consumers seek easier access.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Domino's Pizza's 30-minute delivery guarantee was responsible for the chain's 1980s surge, but it was discontinued after the company was found liable for delivery driver accidents.

Despite being favored by 87% of Americans, Congress does not have term limits.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.