Body Systems

All eye colors are an interaction of brown pigment and light, but some eye colors occur much less often than others. Here are the six you'll see the least.

By Jesslyn Shields

Surely you've had the wind knocked out of you at some point in your life. But what's really going on inside your body?

By Dominique Michelle Astorino

Saliva is not exactly the most appetizing of subjects, but it plays an important role in everything from how food tastes to how it is digested.

By Jennifer Walker-Journey

The presence of a protein called Piezo1 plays a key role in how tendons heal – and a genetic mutation in that protein may also enhance athletic performance and keep us moving around longer and better.

By Hiroshi Asahara & Ryo Nakamichi

Believe it or snot, almost every living creature has some kind of mucus — because mucus does so many things. A study found mucus was so beneficial to mammals, it evolved independently in species.

By Jennifer Walker-Journey

Surely you've had a knot in your neck at some point. But your muscles really aren't tied in knots. Or are they?

By Zachary Gillen

Having kidney stones can feel like you've been stabbed in the back. But is it the stones causing the searing pain or is it something else?

By Dave Roos

We've all heard of the brain's gray matter, but what about the white matter? What does it do?

By Christopher Filley

The director of the Aphasia Research Laboratory at Boston University explains the condition forcing Bruce Willis to retire from acting, including what treatment options could be available.

By Swathi Kiran

Maybe you've seen those fantastical stories saying the world's longest piece of poop is 26 feet? Is that even possible? Where does crap like this come from?

By Alia Hoyt

Many things play a role in how our bodies acclimate to super-cold temperatures, including our own habits, genetics and even brown fat.

By Allison Troutner

Nearly all newborns have some shade of blue eyes at birth. But after a few months, they change. What's going on?

By Allison Troutner

Knowing your eye shape can help with everything from selecting eyeglass frames to shaping the perfect brow.

By Laurie L. Dove

The Fugate and the Combs families in rural Kentucky lost the genetic lottery, as both shared a rare recessive trait that made their skin look blue. What happened to the blue people of Kentucky?

By Dave Roos

Stanford researchers have developed a new white cane, incorporating sensing and wayfinding approaches from robotics and self-driving vehicles. Could this new white cane reshape life for the visually impaired?

By Allison Troutner

Parosmia is a post-COVID-19 side effect that distorts your sense of taste and smell. But smell training (you read that right) can help most people get things back on track.

By Jennifer Walker-Journey

Technology for hearing aids has advanced drastically since our grandparents wore those big, bulky ones wrapped around their ears. Now they're Bluetooth-enabled and can even translate foreign languages on the fly.

By Patrick J. Kiger

Does using a bathroom other than your own freak you out? The Faux Fan drowns out the sounds your body makes when you have to, well, go, so you can poop without worrying people will hear.

By Meg Sparwath

Empty nose syndrome is a rare problem where patients have clear nasal passages but constant sensations of being unable to breathe. And worst of all, many doctors believe it's all in their heads.

By Jennifer Walker-Journey

Savant syndrome is a rare condition in which someone with significant mental disabilities demonstrates certain unexplained extraordinary abilities, such as playing music or remembering prodigious amounts of information.

By Jesslyn Shields

We've probably all been breathing wrong our entire lives. Why is that? Experts suggest we should focus on breathing through our noses and most of us don't.

By Jennifer Walker-Journey

There are eight major blood types and some are more common than others. But what's the rarest of them all?

By Jennifer Walker-Journey

Proprioception refers to our ability to perceive our body's position and how we move through space. It's often considered our sixth sense because we do it without thinking about it.

By Jennifer Walker-Journey

Blue light glasses are super popular these days. But do they work the way marketers promise?

By John Perritano

Although the inability to picture things in your head would seem to be a hinderance, some experts say it's definitely not a creativity killer and actually can have some advantages.

By Alia Hoyt