How is it that a breathalyzer can measure the alcohol content in someone’s blood, hours after they had their last drink, based on their breath alone? And could we use this same technology to detect disease by analyzing a person’s...

In the first of a new TED-Ed series designed to catalyze curiosity, TED Curator Chris Anderson shares his boyhood obsession with quirky questions that seem to have no answers.

The bubonic plague, which killed around 1/5 of the world's population in the 14th century, is still around today -- but it now claims only a few thousand lives each year. How did that number shrink so drastically? Sharon N. DeWitte...

Diabetes has a history dating back to Ancient Greece. Our treatment of it, however, is more recent and was originally made possible with the help of man's best friend. Due to physiological traits shared with humans, dogs have saved...

Why would a fish throw up its stomach? What makes a scuba diver develop painful microbubbles in their joints? Neosha S Kashef details the basics of barotrauma, shedding light on how humans and fish alike are influenced by laws of physics...

There's no better way to stop a disease than to catch and treat it early, before symptoms occur. That's the whole point of medical screening techniques like radiography, MRIs and blood tests. But there's one medium with overlooked...

Being able to sense time helps us do everything from waking and sleeping to knowing precisely when to catch a ball that's hurtling towards us. And we owe all these abilities to an interconnected system of timekeepers in our brains. But...

For most of human history, we have sought to treat and cure diseases. But only in recent decades did it become possible to ensure that a particular disease never threatens humanity again. Julie Garon and Walter A. Orenstein detail how...

A condition called Charles Bonnet Syndrome can cause blind patients to hallucinate scenes in vivid color. fMRI studies show that these hallucinations activate the same brain areas as sight - areas that are not activated by imagination....

Body odor is usually normal, but when it's extreme it can be a sign of something gone wrong.

Get informed on the causes and risks of human papillomavirus, HPV, and how to protect yourself from the infection. -- At some point, most sexually active people will be infected with human papillomavirus, or HPV. There are over 100...

Have you ever wondered what happens to a painkiller, like ibuprofen, after you swallow it? Medicine that slides down your throat can help treat a headache, a sore back, or a throbbing sprained ankle. But how does it get where it needs to...

If you are a living, breathing human being, chances are you have felt sad at least a few times in your life. But what exactly is melancholy, and what (if anything) should we do about it? Courtney Stephens details our still-evolving...

The highly virulent Ebola virus has seen a few major outbreaks since it first appeared in 1976 -- with the worst epidemic occurring in 2014. How does the virus spread, and what exactly does it do to the body? Alex Gendler details what...

In ancient Greece, the best-known remedy for a long-standing headache was to drill a small hole in the skull to drain supposedly infected blood. Fortunately, doctors today don't resort to power tools to cure headaches, but we still have...

In the United States, it's estimated that 30 percent of adults and 66 percent of adolescents are regularly sleep-deprived. This isn't just a minor inconvenience: staying awake can cause serious bodily harm. Claudia Aguirre shows what...

Visiting the bathroom is part of the daily human experience. But occasionally, constipation, a condition that causes a backup in your digestive system, strikes. In some especially uncomfortable cases, the food you eat can take several...

Imagine you're fast asleep and then suddenly awake. You want to move but can't, as if someone is sitting on your chest. And you can't even scream! This is sleep paralysis, a creepy but common phenomenon caused by an overlap in REM sleep...

Humans should urinate at least four to six times a day, but occasionally, the pressures of modern life force us to clench and hold it in. How bad is this habit, and how long can our bodies withstand it? Heba Shaheed takes us inside the...

Learn why tuberculosis, TB, is the world’s most infectious disease and how medical advancements are improving treatment. -- In 2008, two 9,000-year old skeletons were found with their bones infected by an all too familiar bacterium....

Cigarettes aren't good for us. That's hardly news -- we've known about the dangers of smoking for decades. But how exactly do cigarettes harm us, and can our bodies recover if we stop? Krishna Sudhir details what happens when we smoke --...

Depression is the leading cause of disability in the world; in the United States, close to ten percent of adults struggle with the disease. But because it's a mental illness, it can be a lot harder to understand than, say, high...

Prolonged space travel plays a severe toll on the human body: microgravity impairs muscle and bone growth, and high doses of radiation cause irreversible mutations. As we seriously consider the human species becoming space-faring, a big...

If you've been to a restaurant in the last few years, you've likely seen the words gluten-free written somewhere on the menu. But what exactly is gluten, and why can't some people process it? And why does it only seem to be a problem...