Dengue is sometimes called 'breakbone fever' because it's so painful

Wolbachia: the bacteria that could eliminate dengue fever

Dengue fever, transmitted by mosquitoes, kills more people annually than all types of natural disasters combined. However, mosquitoes that host Wolbachia bacterium have their ability to transmit the virus naturally suppressed, offering a route to eliminating nearly 25,000 deaths annually.

Ebola has an average fatality rate above 50%

The Ebola virus is one of the planet’s most feared bugs. Symptoms begin with fever and fatigue but quickly develop into severe vomiting, diarrhea, and internal and external bleeding. But why is it so deadly? In short, Ebola hijacks the immune system to rapidly make replicas of itself.

See this diverse list of vector-borne diseases

Human illnesses caused by parasites, viruses, and bacteria, and transmitted by a living organism—often small, bloodsucking ones like mosquitoes, ticks, and sandflies—are known as vector-borne diseases. That carrier is called a vector. These diseases disproportionately affect the poorest populations in tropical and subtropical areas.

Most cases of West Nile virus are asymptomatic in people

About 1 in 5 infected people develop symptoms from West Nile, including symptoms such as fatigue, head and body aches, and vomiting. But around 1% of patients develop severe complications such as encephalitis or meningitis, which can be life-threatening. Those who are most likely to become severely ill are people over age 60.

Hear what it's like to have malaria

In Kenya, as one malaria-sufferer explains, the disease is common enough that anytime a child has a fever or any sort of sickness families and the community will wonder if it's malaria. Sleeping under a mosquito net is recommended. Unfortunately, a gin and tonic will not keep malaria at bay.

Treating black fever can result in a complication that spreads the deadly disease

Black fever, a deadly parasitic disease second only to malaria, threatens more than 1 billion people across more than 83 countries. Also known as kala-azar or visceral leishmaniasis, the disease is caused by parasites that spread through sandfly...

Zika virus shocked scientists because the mosquito-borne disease causes birth defects

This revelation, confirmed in 2016, marked the first time that a mosquito-borne disease was known to cause birth defects. Fetuses exposed to the Zika virus during pregnancy sometimes suffer from neurological complications and microcephaly, a small-headed condition associated with neurological development issues and impairment.

The most severe form of malaria is caused by the Plasmodium falciparum parasite

Multiple species of a single-celled organism called a protozoa cause malaria infection when transmitted by a mosquito bite. But Plasmodium falciparum is the most widespread in Africa, and the most deadly.

'Sloth fever' is an emerging health threat, especially to pregnant women

This disease, caused by the Oropouche virus, is found in animals including sloths, primates, and birds. It primarily spreads through the bite of midges—insects commonly called "no-see-ums." It's endemic to the Amazon region, but US travelers are increasingly contracting it internationally.

The 'kissing bug disease' occurs when a bug's parasite-laden poop gets into your blood

Chagas disease transmission can occur when triatomine bugs bite someone infected with a Trypanosoma cruzi parasite and then bite someone else, passing on the pathogen, though the parasite can also be transmitted in other ways, including via food, congenitally, and through blood transfusions. The bugs tend to feed at night and can bite anywhere on the body, but their reputation for biting people around the mouth and eyes created the idea that the bugs were "kissing" humans. Recent research suggests the disease may be endemic in the US.

HFMD symptoms typically begin to show up 3-6 days after exposure

Fever is often the first symptom and then painful sores may develop a day or two later. Coxsackie A16 is currently the most common enterovirus that leads to the disease, though there are several other enteroviruses that can cause it as well.

Marburg virus, related to Ebola, is also extremely deadly, and has no available vaccine.

Ebola is a filovirus, meaning it resembles a thread under a microscope, though it sometimes twists and can resemble a bowl of spaghetti.

The rare but deadly time bomb lurking after a measles infection

Subacute sclerosing panencephalitis, also known as Dawson disease, is a progressive and fatal neurodegenerative condition caused by a dormant measles infection. Typically, patients recover from measles normally, with the symptoms of SSPE only appearing years or even decades later. The incidence rate in unvaccinated pediatric patients is estimated to be around one in 1,300.

Yellow fever sidelined more US troops than enemy fire during the Spanish-American War

The disease, transmitted by the Aedes aegypti mosquito, sickened more than 2,000 soldiers. Fewer than 400 American soldiers died in the 1898 war.

Typhoid smells like freshly baked brown bread

Certain ailments are associated with documented scents, including diabetes, Parkinson's disease, and typhoid. The skin of people with yellow fever, for example, can smell like a "butcher shop."

Lupus, an autoimmune disease with varied symptoms, was named for wolf bite-like lesions

The 13th-century physician behind the name (lupus is Latin for wolf) named it after a patient he saw who had facial lesions that looked to him like a wolf's bite. Other common symptoms of the disease include extreme fatigue, painful and swollen joints, fevers, and light sensitivity.

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.

The flu is a contagious respiratory illness caused by influenza viruses

Unlike the common cold, influenza attacks suddenly with fever, body aches, and fatigue. Seasonal strains circulate worldwide, infecting up to a billion people each year and causing hundreds of thousands of deaths despite vaccines and treatments.

What is the most painful thing in the world?

Pain is famously difficult to quantify, and though our response to it may be subjective, most pain does have underlying objective causes. So what's the most painful thing of all? Many say childbirth, or a broken femur, but this article lays out one case for why, of all things, kidney stones may be the most painful experience. Prepare yourself to find out here.

Learn about the basic anatomy of mosquitoes

This short explainer video breaks down the mosquito's general body components, highlighting how mosquitoes breathe, fly, and more. It also touches on how experts can tell different mosquito species apart.

Foot-and-mouth disease, which affects animals, has been eradicated in many locations

The disease, which causes fevers and painful blistering in the mouth, muzzle, snout, teats, and feet—somewhat similar to hand, foot, and mouth disease in people—is transmitted via contact with infected animals or their fluids or eating infected foods or meat. Though it primarily affects cloven-hoofed animals, it's also been known to sicken camels and even elephants.

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.

Cholera was called the 'Blue Death'

In the mid-1800s—when John Snow identified cholera in London—the disease was known simply as the "Blue Death." That's because blood would thicken in patients' veins when they were struggling with extreme dehydration. As a result, their skin would turn a blueish hue as their blood was starved of oxygen.

Lyme disease may cost about $1B annually in the US

The economic burden of the disease in this estimate includes direct medical costs and societal costs, including productivity losses. It does not include suspected, undiagnosed, or nonacute cases, which would push that figure upward.

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.

Fiji's 'quiet' diabetes crisis

Across the Pacific archipelago of Fiji, diabetes often avoids diagnosis until amputation or death is imminent. Fiji's government has said nearly 30% of its population has diabetes, and, in 2019, related amputations accounted for 40% of the country's hospital operations. This "sugar disease" may have such a stronghold on the archipelago, which has a physically active culture that prizes locally sourced foods, due to cost, with processed foods being much cheaper than alternatives.

Ménière's disease is a long-term, inner ear disorder that causes vertigo

This severe vertigo-causing disorder may involve long and recurrent episodes of vertigo. Symptoms of this disease include balance issues and hearing loss, tinnitus, and a feeling of fullness in the ear. It typically affects only one ear and is linked to a buildup of excess fluid in the inner ear.

Explore what it's like inside a patient isolation unit, used in situations such as treating a patient or suspected patient with Ebola.

How the most famous Ebola book, The Hot Zone, which sold 3.5 million copies and was translated into 30 languages, got aspects of the disease so wrong.

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

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

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.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

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

See these 16 pieces of art evoking phobias of snakes, flying, spiders, and more. 

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail

During the French Revolution, a botanist's letter asking about "dear Rhus" (poison ivy) was intercepted, leading authorities to suspect he was conspiring with the Russians.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

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

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

NBA superstar Victor Wembanyama spent the 2025 summer training with monks in central China to enhance his body and mind.

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

El Niño, Spanish for 'the boy,' was named after Jesus Christ because the phenomenon resembled the weather changes observed around Christmastime.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.