Since humanity’s earliest days, we’ve been plagued by countless disease-causing pathogens. Invisible and persistent, these microorganisms and the illnesses they incur have killed more humans than anything else in history. But which disease has been the deadliest? Dan Kwartler digs into how human progress and innovation throughout history exposed us to surprising new maladies. This TED-Ed lesson was directed by BASA, narrated by Addison Anderson and the music was created by Igor Figueroa, Estudio Mono.

The diseases that changed humanity forever | Dan Kwartler

What does exercise do to your brain? Can psychedelics treat depression? From smart daily habits to new medical breakthroughs, welcome to TED Health, with host Dr. Shoshana Ungerleider. TED speakers answer questions you never even knew you had, and share ideas you won't hear anywhere else, all around how we can live healthier lives.

Health & Fitness

Isn’t it odd that, when something’s funny, you might show your teeth, change your breathing, become weak and achy in some places, and maybe even cry? In other words, why do we do this bizarre thing that is laughter? Since there’s no archaeological record of laughter, it’s impossible to say exactly how and why it evolved, but scientists have some theories. Sasha Winkler digs into the reflex. This TED-Ed lesson was directed by Hanna Rybak, narrated by Susan Zimmerman and the music is by Jarrett Farkas.

The science of laughter | Sasha Winkler

Catching cancer at its earliest stages saves lives. But in a body made up of trillions of cells, how do you spot a small group of rogue cancer cells? Biomedical researcher Hani Goodarzi discusses his lab's discovery of a new class of RNAs that, when paired with emerging AI tools, could help detect cancer earlier, more precisely and even through routine blood work — potentially transforming our understanding of the disease.

What if a simple blood test could detect cancer? | Hani Goodarzi

Having your period is exhausting — and for many people across the world, menstruation is even more challenging because of stigmas and difficulty getting basic hygiene supplies, says social activist Ananya Grover. In this uplifting, actionable talk, she shares how "Pravahkriti," her campaign to spread period positivity, creatively engages with everyone to promote menstrual health, raise awareness and break taboos around periods. After the talk, Shoshana has a sweeping conversation with OB/GYN, activist and fellow TED Audio Collective host Dr. Jen Gunter on breaking down period myths and misconceptions.

A campaign for period positivity | Ananya Grover

Biologist Kathleen McAuliffe dives into emerging research that explores how certain gut bacteria can influence major parts of who you are, from your personality to life-changing neurological disorders. Learn more about how this ongoing clinical medical and pharmaceutical research might change how we treat disease — and discover the impact of your internal microbial makeup on your mood, weight and more.

The diseases that changed humanity forever | Dan Kwartler

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