The bubonic plague spread in three waves over 600 years

Volcanoes in the 1340s likely helped trigger the Black Death

The "bubonic plague" that wiped out roughly half of Europe and Asia originated from many factors. Recent research suggests volcanic eruptions contributed as well. The "aerosol" effects of matter released from eruptions likely prompted famine and accelerated the spread of infected fleas riding on grains avoiding spoilage.

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.

Hear how the Black Death reshaped Europe's economy

The Black Death killed tens of millions across Europe, but the labor shortages that followed shifted economic power. With fewer workers available, survivors demanded higher wages and better conditions—sparking what historians call a medieval “Golden Age of Labor.”

Europe’s first recorded influenza pandemic swept the continent in 1580

The 1580 influenza pandemic, traced from Asia to Africa and into Europe, became the first flu outbreak clearly documented across the continent—killing tens of thousands and highlighting influenza’s potential for rapid global spread.

A timeline of major pandemics from 1899–2025

Modern pandemics have been defined by the race between globalization (which increases risk) and the development of new medicines. The Great Influenza epidemic claimed some 50 million lives, and the COVID-19 pandemic killed more than 7 million. In between, diseases like Ebola, cholera, AIDS, and more have devastated communities.

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...

Vector-borne diseases kill more than 700,000 people globally each year—and are growing

The diseases with the greatest potential to spread widely aren't the ones that quickly kill human hosts. Instead, the best hosts or reservoirs for vector-borne diseases would be chronically ill over the long term, increasing the likelihood that the pathogen could be transmitted to others.

Play 17th-century death roulette

Before modern science and medicine, death was much harder to escape. Using real mortality records from London's Dreadful Visitation–a collection of all the Bills of Mortality from 1665–this interactive game gives you an idea of what may have possibly killed you during the Great Plague. Grow your appreciation for life today as you stumble upon causes of death like “livergrown” and “drowned at St. Katharine’s by the Tower”.

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.

See how Ebola tore through Guinea, Sierra Leone, and Liberia in 2014-2016.

Lyme disease is caused by bacteria transmitted through the bite of infected ticks

It's an infectious disease caused by Borrelia burgdorferi bacteria. It's spread through the bite of two species of infected ticks, the Western blacklegged ticks on the West Coast, and Blacklegged ticks found throughout the eastern US. The ticks can transmit the disease at both the nymph and adult stage. It's not known to be transmitted from one person to another via kissing or sex.

During the COVID-19 pandemic, readers returned to Camus' 'The Plague'

The 1947 novel, about a city in Algeria that enacts a city-wide quarantine to battle a deadly outbreak, captured readers' attention in the early months of 2020. In the UK, over 2,000 copies of the book were sold in March of that year, over six times what it had sold the month before.

European diseases killed a massive share of the Native American population

After Western contact, epidemic diseases devastated Indigenous communities. By 1920, the Native American population of the US had fallen to roughly 270,000, compared with an estimated 1.2 to 18 million at the time of European arrival.

How royal panic led to Europe's deadliest witch hunts

This article delves into the witch "panics" and hunts that roiled across Scotland between 1590 and 1662. The witch hunts in Scotland were unusually deadly, with the country having five times the average European execution rate per capita. Their...

The history of germ theory, which explains that illnesses are caused by microorganisms

For centuries, the miasma theory, which held that illnesses were caused by clouds of "bad air" produced by decaying organic matter, was the accepted explanation for the spread of disease. The development of microscopes and the subsequent technology to isolate bacteria and test disease spread in mice greatly contributed to contagionists overturning miasmatists.

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.

Neglected tropical diseases affect more people than the population of Europe

This group of conditions, which includes hookworm, sickens roughly one in seven people on the planet—a tally which dwarfs Europe's population of roughly 450 million. International cooperation and donations are helping to control some of these illnesses, which can be caused by parasites, viruses, and bacteria. They're all treatable or preventable, but primarily occur among poor, isolated communities that may not receive adequate care.

Illustrating the beginning and end of WWI through maps

In August of 1914, Germany invaded an ostensibly neutral Belgium, kick-starting World War I. The war became one of the deadliest conflicts in human history, decimating Europe and reshaping global politics for the next century. It also brought forward sweeping and terrifying new military technologies, a product of the Industrial Revolution. Explore 40 maps explaining the Great War in detail.

The canal carried germs as well as goods

In 1832, North America’s first cholera epidemic spread inland by way of the Erie Canal, carried by immigrants arriving on ships. Fearful towns barred passengers from disembarking, yet cholera, smallpox, and other diseases still traveled the waterway.

The Great Depression was an international depression felt far beyond the US

Many countries suffered through a depression in the 1930s that the First World War, the US stock market crash, and an economic downturn in Germany turned into an international crisis.

Penicillin slashed battlefield pneumonia deaths during World War II

Before antibiotics, bacterial pneumonia killed about 18% of infected soldiers in World War I. By World War II, penicillin cut that death rate to less than 1%.

When was the first blood transfusion?

In the 1600s, an English doctor transferred the blood from one dog to another via quills. The procedure ended when one of the dogs died. This article details the early days of blood transfusions, which turned toward humans shortly after the 1666 dog experiment and involved putting the blood of a sheep into a human recipient (who reportedly survived the encounter).

See how the Ebola virus affects blood circulation in the human body

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

There were roughly 17 Black Friday-related deaths and 125 injuries between 2006 and 2021

A website called Black Friday Death Count or “BFDC” scrapes news headlines for Black Friday-related deaths and injuries reported around the world. It includes the overall count of Black-Friday related deaths, as well as the context for each of them.

Who died during the French Revolution of 1789?

This article examines the human cost of the 1789 French Revolution, during which up to 17,000 people were guillotined and many more were killed by other means. A majority of the guillotine deaths were meted out during the Reign of Terror, a...

Explore the cost of major viruses and other malware incidents through 2017

The first significant malware was the Morris worm in 1988, which caused an estimated $10,000 to $10M in damage to computers. With $38B in damage caused, Mydoom is the most costly piece of malware in history. Spread via email and, at one point, accounting for about 25% of all messages sent worldwide, the malware infected computers to create a botnet that launched cyberattacks.

The final war between the Persian and Byzantine empires

The Arab conquests of the seventh century, which swept over Egypt, Syria, and Mesopotamia, were made possible by a catastrophic generation-long war between the Byzantine and Persian Empires. That war, in turn, was the last act in a struggle that had gone on for centuries, and shaped the whole subsequent history of the Middle East.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in terms of casualties, forces mobilized, and displacement of civilians.

11 people died from firework injuries in the US in 2024.

Between 10 million and 50 million people in the US develop rashes from poison ivy, poison sumac, and poison oak each year.

Elk Cloner, the first computer virus to spread in public, was written as a practical joke by Richard Skrenta, a Pittsburgh high school student.

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

Roughly 43 million US borrowers owe roughly $1.7T in student debt, the second-largest source of consumer debt behind mortgages.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

The term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

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

The Beatles' US label rejected the band's first two singles, 'Please Please Me' and 'From Me to You,' with one executive calling the band 'dead in the water.'

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

Explore chaos in this simulation of two double pendulums, where small differences in the release angles produce wildly different outcomes.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

See 33 images that became central to huge scandals, including a young Charles and Camilla, Michael Jackson's baby on a hotel balcony, and Hugh Grant's mugshot.

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.